Programs & Examples On #Test data

Parameter "stratify" from method "train_test_split" (scikit Learn)

Scikit-Learn is just telling you it doesn't recognise the argument "stratify", not that you're using it incorrectly. This is because the parameter was added in version 0.17 as indicated in the documentation you quoted.

So you just need to update Scikit-Learn.

How to generate sample XML documents from their DTD or XSD?

I think Oxygen (http://www.oxygenxml.com/) does it as well, but that's another commerical product. It's a nice one, though... I'd strongly recommend it for anyone doing a lot of XML work. It comes in a nice Eclipse plugin, too.

I do believe there is a free, fully-featured 30 day trial.

Sample database for exercise

Why not download the English Wikipedia? There are compressed SQL files of various sizes, and it should certainly be large enough for you

The main articles are XML, so inserting them into the db is a bit more of a problem, but you might find there are other files there that suit you. For example, the inter-page links SQL file is 2.3GB compressed. Have a look at https://en.wikipedia.org/wiki/Wikipedia:Database_download for more info.

Oskar

Is there a Social Security Number reserved for testing/examples?

To expand on the Wikipedia-based answers:

The Social Security Administration (SSA) explicitly states in this document that the having "000" in the first group of numbers "will NEVER be a valid SSN":

I'd consider that pretty definitive.

However, that the 2nd or 3rd groups of numbers won't be "00" or "0000" can be inferred from a FAQ that the SSA publishes which indicates that allocation of those groups starts at "01" or "0001":

But this is only a FAQ and it's never outright stated that "00" or "0000" will never be used.

In another FAQ they provide (http://www.socialsecurity.gov/employer/randomizationfaqs.html#a0=6) that "00" or "0000" will never be used.

I can't find a reference to the 'advertisement' reserved SSNs on the SSA site, but it appears that no numbers starting with a 3 digit number higher than 772 (according to the document referenced above) have been assigned yet, but there's nothing I could find that states those numbers are reserved. Wikipedia's reference is a book that I don't have access to. The Wikipedia information on the advertisement reserved numbers is mentioned across the web, but many are clearly copied from Wikipedia. I think it would be nice to have a citation from the SSA, though I suspect that now that Wikipedia has made the idea popular that these number would now have to be reserved for advertisements even if they weren't initially.

The SSA has a page with a couple of stories about SSN's they've had to retire because they were used in advertisements/samples (maybe the SSA should post a link to whatever their current policy on this might be):

Get value from text area

Vanilla JS

document.getElementById("textareaID").value

jQuery

$("#textareaID").val()

Cannot do the other way round (it's always good to know what you're doing)

document.getElementById("textareaID").value() // --> TypeError: Property 'value' of object #<HTMLTextAreaElement> is not a function

jQuery:

$("#textareaID").value // --> undefined

How do I restore a dump file from mysqldump?

You can try SQLyog 'Execute SQL script' tool to import sql/dump files.

enter image description here

Upload a file to Amazon S3 with NodeJS

var express = require('express')

app = module.exports = express();
var secureServer = require('http').createServer(app);
secureServer.listen(3001);

var aws = require('aws-sdk')
var multer = require('multer')
var multerS3 = require('multer-s3')

    aws.config.update({
    secretAccessKey: "XXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
    accessKeyId: "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX",
    region: 'us-east-1'
    });
    s3 = new aws.S3();

   var upload = multer({
   storage: multerS3({
    s3: s3,
    dirname: "uploads",
    bucket: "Your bucket name",
    key: function (req, file, cb) {
        console.log(file);
        cb(null, "uploads/profile_images/u_" + Date.now() + ".jpg"); //use  
     Date.now() for unique file keys
    }
  })
   });

 app.post('/upload', upload.single('photos'), function(req, res, next) {

 console.log('Successfully uploaded ', req.file)

 res.send('Successfully uploaded ' + req.file.length + ' files!')

})

What is the difference between Integer and int in Java?

To optimize the Java code runtime, int primitive type(s) has been added including float, bool etc. but they come along with there wrapper classes so that if needed you can convert and use them as standard Java object along with many utility that comes as their member functions (such as Integer.parseInt("1")).

How to scroll to top of the page in AngularJS?

You can use $anchorScroll.

Just inject $anchorScroll as a dependency, and call $anchorScroll() whenever you want to scroll to top.

Comparison of Android Web Service and Networking libraries: OKHTTP, Retrofit and Volley

Adding to the accepted answer and what LOG_TAG said....for Volley to parse your data in a background thread you must subclass Request<YourClassName> as the onResponse method is called on the main thread and parsing on the main thread may cause the UI to lag if your response is big. Read here on how to do that.

Python spacing and aligning strings

Resurrecting another topic, but this may come in handy for some.

With a little bit of inspiration from https://pyformat.info you can build a method to get a Table of Content [TOC] style printout.

# Define parameters
Location = '10-10-10-10'
Revision = 1
District = 'Tower'
MyDate = 'May 16, 2012'
MyUser = 'LOD'
MyTime = '10:15'

# This is just one way to arrange the data
data = [
    ['Location: '+Location, 'Revision:'+str(Revision)],
    ['District: '+District, 'Date: '+MyDate],
    ['User: '+MyUser,'Time: '+MyTime]
]

# The 'Table of Content' [TOC] style print function
def print_table_line(key,val,space_char,val_loc):
    # key:        This would be the TOC item equivalent
    # val:        This would be the TOC page number equivalent
    # space_char: This is the spacing character between key and val (often a dot for a TOC), must be >= 5
    # val_loc:    This is the location in the string where the first character of val would be located

    val_loc = max(5,val_loc)

    if (val_loc <= len(key)):
        # if val_loc is within the space of key, truncate key and
        cut_str =  '{:.'+str(val_loc-4)+'}'
        key = cut_str.format(key)+'...'+space_char

    space_str = '{:'+space_char+'>'+str(val_loc-len(key)+len(str(val)))+'}'
    print(key+space_str.format(str(val)))

# Examples
for d in data:
    print_table_line(d[0],d[1],' ',30)

print('\n')
for d in data:
    print_table_line(d[0],d[1],'_',25)

print('\n')
for d in data:
    print_table_line(d[0],d[1],' ',20)

The resulting output is as follows:

Location: 10-10-10-10         Revision:1
District: Tower               Date: May 16, 2012
User: LOD                     Time: 10:15


Location: 10-10-10-10____Revision:1
District: Tower__________Date: May 16, 2012
User: LOD________________Time: 10:15


Location: 10-10-... Revision:1
District: Tower     Date: May 16, 2012
User: LOD           Time: 10:15

multiprocessing.Pool: When to use apply, apply_async or map?

Here is an overview in a table format in order to show the differences between Pool.apply, Pool.apply_async, Pool.map and Pool.map_async. When choosing one, you have to take multi-args, concurrency, blocking, and ordering into account:

                  | Multi-args   Concurrence    Blocking     Ordered-results
---------------------------------------------------------------------
Pool.map          | no           yes            yes          yes
Pool.map_async    | no           yes            no           yes
Pool.apply        | yes          no             yes          no
Pool.apply_async  | yes          yes            no           no
Pool.starmap      | yes          yes            yes          yes
Pool.starmap_async| yes          yes            no           no

Notes:

  • Pool.imap and Pool.imap_async – lazier version of map and map_async.

  • Pool.starmap method, very much similar to map method besides it acceptance of multiple arguments.

  • Async methods submit all the processes at once and retrieve the results once they are finished. Use get method to obtain the results.

  • Pool.map(or Pool.apply)methods are very much similar to Python built-in map(or apply). They block the main process until all the processes complete and return the result.

Examples:

map

Is called for a list of jobs in one time

results = pool.map(func, [1, 2, 3])

apply

Can only be called for one job

for x, y in [[1, 1], [2, 2]]:
    results.append(pool.apply(func, (x, y)))

def collect_result(result):
    results.append(result)

map_async

Is called for a list of jobs in one time

pool.map_async(func, jobs, callback=collect_result)

apply_async

Can only be called for one job and executes a job in the background in parallel

for x, y in [[1, 1], [2, 2]]:
    pool.apply_async(worker, (x, y), callback=collect_result)

starmap

Is a variant of pool.map which support multiple arguments

pool.starmap(func, [(1, 1), (2, 1), (3, 1)])

starmap_async

A combination of starmap() and map_async() that iterates over iterable of iterables and calls func with the iterables unpacked. Returns a result object.

pool.starmap_async(calculate_worker, [(1, 1), (2, 1), (3, 1)], callback=collect_result)

Reference:

Find complete documentation here: https://docs.python.org/3/library/multiprocessing.html

What is the difference between `let` and `var` in swift?

var is the only way to create a variables in swift. var doesn't mean dynamic variable as in the case of interpreted languages like javascript. For example,

var name = "Bob"

In this case, the type of variable name is inferred that name is of type String, we can also create variables by explicitly defining type, for example

var age:Int = 20

Now if you assign a string to age, then the compiler gives the error.

let is used to declare constants. For example

let city = "Kathmandu"

Or we can also do,

let city:String = "Kathmandu"

If you try to change the value of city, it gives error at compile time.

How to copy commits from one branch to another?

git cherry-pick : Apply the changes introduced by some existing commits

Assume we have branch A with (X, Y, Z) commits. We need to add these commits to branch B. We are going to use the cherry-pick operations.

When we use cherry-pick, we should add commits on branch B in the same chronological order that the commits appear in Branch A.

cherry-pick does support a range of commits, but if you have merge commits in that range, it gets really complicated

git checkout B
git cherry-pick SHA-COMMIT-X
git cherry-pick SHA-COMMIT-Y
git cherry-pick SHA-COMMIT-Z

Example of workflow :

enter image description here

We can use cherry-pick with options

-e or --edit : With this option, git cherry-pick will let you edit the commit message prior to committing.

-n or --no-commit : Usually the command automatically creates a sequence of commits. This flag applies the changes necessary to cherry-pick each named commit to your working tree and the index, without making any commit. In addition, when this option is used, your index does not have to match the HEAD commit. The cherry-pick is done against the beginning state of your index.

Here an interesting article concerning cherry-pick.

XPath: Get parent node from child node

This works in my case. I hope you can extract meaning out of it.

//div[text()='building1' and @class='wrap']/ancestor::tr/td/div/div[@class='x-grid-row-checker']

c# open a new form then close the current form?

private void buttonNextForm(object sender, EventArgs e)
{
    NextForm nf = new NextForm();//Object of the form that you want to open
    this.hide();//Hide cirrent form.
    nf.ShowModel();//Display the next form window
    this.Close();//While closing the NextForm, control will come again and will close this form as well
}

Arithmetic operation resulted in an overflow. (Adding integers)

The maximum value of an integer (which is signed) is 2147483647. If that value overflows, an exception is thrown to prevent unexpected behavior of your program.

If that exception wouldn't be thrown, you'd have a value of -2145629296 for your Volume, which is most probably not wanted.

Solution: Use an Int64 for your volume. With a max value of 9223372036854775807, you're probably more on the safe side.

Using jQuery to test if an input has focus

if anyone cares there is a much better way to capture focus now, $(foo).focus(...)

http://api.jquery.com/focus/

How to Store Historical Data

In SQL Server 2016 and above, there is a new feature called Temporal Tables that aims to solve this challenge with minimal effort from developer. The concept of temporal table is similar to Change Data Capture (CDC), with the difference that temporal table has abstracted most of the things that you had to do manually if you were using CDC.

Javascript code for showing yesterday's date and todays date

Yesterday's date is simply today's date less one, so:

var d = new Date();
d.setDate(d.getDate() - 1);

If today is 1 April, then it is set to 0 April which is converted to 31 March.

Since you also wanted to do some other stuff, here are some functions to do it:

// Check if d is a valid date
// Must be format year-month name-date
// e.g. 2011-MAR-12 or 2011-March-6
// Capitalisation is not important
function validDate(d) {
  var bits = d.split('-');
  var t = stringToDate(d);
  return t.getFullYear() == bits[0] && 
         t.getDate() == bits[2];
}

// Convert string in format above to a date object
function stringToDate(s) {
  var bits = s.split('-');
  var monthNum = monthNameToNumber(bits[1]);
  return new Date(bits[0], monthNum, bits[2]);
}

// Convert month names like mar or march to 
// number, capitalisation not important
// Month number is calendar month - 1.
var monthNameToNumber = (function() {
  var monthNames = (
     'jan feb mar apr may jun jul aug sep oct nov dec ' +
     'january february march april may june july august ' +
     'september october november december'
     ).split(' ');

  return function(month) {
    var i = monthNames.length;
    month = month.toLowerCase(); 

    while (i--) {
      if (monthNames[i] == month) {
        return i % 12;
      }
    }
  }
}());

// Given a date in above format, return
// previous day as a date object
function getYesterday(d) {
  d = stringToDate(d);
  d.setDate(d.getDate() - 1)
  return d;
}

// Given a date object, format
// per format above
var formatDate = (function() {
  var months = 'jan feb mar apr may jun jul aug sep oct nov dec'.split(' ');
  function addZ(n) {
    return n<10? '0'+n : ''+n;
  }
  return function(d) {
    return d.getFullYear() + '-' + 
           months[d.getMonth()] + '-' + 
           addZ(d.getDate());
  }
}());

function doStuff(d) {

  // Is it format year-month-date?
  if (!validDate(d)) {
    alert(d + ' is not a valid date');
    return;
  } else {
    alert(d + ' is a valid date');
  }
  alert(
    'Date in was: ' + d +
    '\nDay before: ' + formatDate(getYesterday(d))
  );
}


doStuff('2011-feb-08');
// Shows 2011-feb-08 is a valid date
//       Date in was: 2011-feb-08
//       Day before: 2011-feb-07

Convert UTF-8 encoded NSData to NSString

The Swift version from String to Data and back to String:

Xcode 10.1 • Swift 4.2.1

extension Data {
    var string: String? {
        return String(data: self, encoding: .utf8)
    }
}

extension StringProtocol {
    var data: Data {
        return Data(utf8)
    }
}

extension String {
    var base64Decoded: Data? {
        return Data(base64Encoded: self)
    }
}

Playground

let string = "Hello World"                                  // "Hello World"
let stringData = string.data                                // 11 bytes
let base64EncodedString = stringData.base64EncodedString()  // "SGVsbG8gV29ybGQ="
let stringFromData = stringData.string                      // "Hello World"

let base64String = "SGVsbG8gV29ybGQ="
if let data = base64String.base64Decoded {
    print(data)                                    //  11 bytes
    print(data.base64EncodedString())              // "SGVsbG8gV29ybGQ="
    print(data.string ?? "nil")                    // "Hello World"
}

let stringWithAccent = "Olá Mundo"                          // "Olá Mundo"
print(stringWithAccent.count)                               // "9"
let stringWithAccentData = stringWithAccent.data            // "10 bytes" note: an extra byte for the acute accent
let stringWithAccentFromData = stringWithAccentData.string  // "Olá Mundo\n"

Find string between two substrings

This I posted before as code snippet in Daniweb:

# picking up piece of string between separators
# function using partition, like partition, but drops the separators
def between(left,right,s):
    before,_,a = s.partition(left)
    a,_,after = a.partition(right)
    return before,a,after

s = "bla bla blaa <a>data</a> lsdjfasdjöf (important notice) 'Daniweb forum' tcha tcha tchaa"
print between('<a>','</a>',s)
print between('(',')',s)
print between("'","'",s)

""" Output:
('bla bla blaa ', 'data', " lsdjfasdj\xc3\xb6f (important notice) 'Daniweb forum' tcha tcha tchaa")
('bla bla blaa <a>data</a> lsdjfasdj\xc3\xb6f ', 'important notice', " 'Daniweb forum' tcha tcha tchaa")
('bla bla blaa <a>data</a> lsdjfasdj\xc3\xb6f (important notice) ', 'Daniweb forum', ' tcha tcha tchaa')
"""

GROUP BY without aggregate function

That's how GROUP BY works. It takes several rows and turns them into one row. Because of this, it has to know what to do with all the combined rows where there have different values for some columns (fields). This is why you have two options for every field you want to SELECT : Either include it in the GROUP BY clause, or use it in an aggregate function so the system knows how you want to combine the field.

For example, let's say you have this table:

Name | OrderNumber
------------------
John | 1
John | 2

If you say GROUP BY Name, how will it know which OrderNumber to show in the result? So you either include OrderNumber in group by, which will result in these two rows. Or, you use an aggregate function to show how to handle the OrderNumbers. For example, MAX(OrderNumber), which means the result is John | 2 or SUM(OrderNumber) which means the result is John | 3.

How can I get the "network" time, (from the "Automatic" setting called "Use network-provided values"), NOT the time on the phone?

Get the library from http://commons.apache.org/net/download_net.cgi

//NTP server list: http://tf.nist.gov/tf-cgi/servers.cgi
public static final String TIME_SERVER = "time-a.nist.gov";

public static long getCurrentNetworkTime() {
    NTPUDPClient timeClient = new NTPUDPClient();
    InetAddress inetAddress = InetAddress.getByName(TIME_SERVER);
    TimeInfo timeInfo = timeClient.getTime(inetAddress);
    //long returnTime = timeInfo.getReturnTime();   //local device time
    long returnTime = timeInfo.getMessage().getTransmitTimeStamp().getTime();   //server time

    Date time = new Date(returnTime);
    Log.d(TAG, "Time from " + TIME_SERVER + ": " + time);

    return returnTime;
}

getReturnTime() is same as System.currentTimeMillis().

getReceiveTimeStamp() or getTransmitTimeStamp() method should be used.

You can see the difference after setting system time to 1 hour ago.

local time :
System.currentTimeMillis()
timeInfo.getReturnTime()
timeInfo.getMessage().getOriginateTimeStamp().getTime()

NTP server time :
timeInfo.getMessage().getReceiveTimeStamp().getTime()
timeInfo.getMessage().getTransmitTimeStamp().getTime()

How to display with n decimal places in Matlab

You can convert a number to a string with n decimal places using the SPRINTF command:

>> x = 1.23;
>> sprintf('%0.6f', x)

ans =

1.230000

>> x = 1.23456789;
>> sprintf('%0.6f', x)

ans =

1.234568

How do I see active SQL Server connections?

Below is my script to find all the sessions connected to a database and you can check if those sessions are doing any I/O and there is an option to kill them.

The script shows also the status of each session.

Have a look below.

--==============================================================================
-- See who is connected to the database.
-- Analyse what each spid is doing, reads and writes.
-- If safe you can copy and paste the killcommand - last column.
-- Marcelo Miorelli
-- 18-july-2017 - London (UK)
-- Tested on SQL Server 2016.
--==============================================================================
USE master
go
SELECT
     sdes.session_id
    ,sdes.login_time
    ,sdes.last_request_start_time
    ,sdes.last_request_end_time
    ,sdes.is_user_process
    ,sdes.host_name
    ,sdes.program_name
    ,sdes.login_name
    ,sdes.status

    ,sdec.num_reads
    ,sdec.num_writes
    ,sdec.last_read
    ,sdec.last_write
    ,sdes.reads
    ,sdes.logical_reads
    ,sdes.writes

    ,sdest.DatabaseName
    ,sdest.ObjName
    ,sdes.client_interface_name
    ,sdes.nt_domain
    ,sdes.nt_user_name
    ,sdec.client_net_address
    ,sdec.local_net_address
    ,sdest.Query
    ,KillCommand  = 'Kill '+ CAST(sdes.session_id  AS VARCHAR)
FROM sys.dm_exec_sessions AS sdes

INNER JOIN sys.dm_exec_connections AS sdec
        ON sdec.session_id = sdes.session_id

CROSS APPLY (

    SELECT DB_NAME(dbid) AS DatabaseName
        ,OBJECT_NAME(objectid) AS ObjName
        ,COALESCE((
            SELECT TEXT AS [processing-instruction(definition)]
            FROM sys.dm_exec_sql_text(sdec.most_recent_sql_handle)
            FOR XML PATH('')
                ,TYPE
            ), '') AS Query

    FROM sys.dm_exec_sql_text(sdec.most_recent_sql_handle)

) sdest
WHERE sdes.session_id <> @@SPID
  AND sdest.DatabaseName ='yourdatabasename'
--ORDER BY sdes.last_request_start_time DESC

--==============================================================================

Does java.util.List.isEmpty() check if the list itself is null?

No java.util.List.isEmpty() doesn't check if a list is null.

If you are using Spring framework you can use the CollectionUtils class to check if a list is empty or not. It also takes care of the null references. Following is the code snippet from Spring framework's CollectionUtils class.

public static boolean isEmpty(Collection<?> collection) {
    return (collection == null || collection.isEmpty());
}

Even if you are not using Spring, you can go on and tweak this code to add in your AppUtil class.

What is the difference between "screen" and "only screen" in media queries?

The answer by @hybrid is quite informative, except it doesn't explain the purpose as mentioned by @ashitaka "What if you use the Mobile First approach? So, we have the mobile CSS first and then use min-width to target larger sites. We shouldn't use the only keyword in that context, right? "

Want to add in here that the purpose is simply to prevent non supporting browsers to use that Other device style as if it starts from "screen" without it will take it for a screen whereas if it starts from "only" style will be ignored.

Answering to ashitaka consider this example

<link rel="stylesheet" type="text/css" 
  href="android.css" media="only screen and (max-width: 480px)" />
<link rel="stylesheet" type="text/css" 
  href="desktop.css" media="screen and (min-width: 481px)" />

If we don't use "only" it will still work as desktop-style will also be used striking android styles but with unnecessary overhead. In this case, IF a browser is non-supporting it will fallback to the second Style-sheet ignoring the first.

How to create an XML document using XmlDocument?

Working with a dictionary ->level2 above comes from a dictionary in my case (just in case anybody will find it useful) Trying the first example I stumbled over this error: "This document already has a 'DocumentElement' node." I was inspired by the answer here

and edited my code: (xmlDoc.DocumentElement.AppendChild(body))

//a dictionary:
Dictionary<string, string> Level2Data 
{
    {"level2", "text"},
    {"level2", "other text"},
    {"same_level2", "more text"}
}
//xml Decalration:
XmlDocument xmlDoc = new XmlDocument();
XmlDeclaration xmlDeclaration = xmlDoc.CreateXmlDeclaration("1.0", "UTF-8", null);
XmlElement root = xmlDoc.DocumentElement;
xmlDoc.InsertBefore(xmlDeclaration, root);
// add body
XmlElement body = xmlDoc.CreateElement(string.Empty, "body", string.Empty);
xmlDoc.AppendChild(body);
XmlElement body = xmlDoc.CreateElement(string.Empty, "body", string.Empty);
xmlDoc.DocumentElement.AppendChild(body); //without DocumentElement ->ERR



foreach (KeyValuePair<string, string> entry in Level2Data)
{
    //write to xml: - it works version 1.
    XmlNode keyNode = xmlDoc.CreateElement(entry.Key); //open TAB
    keyNode.InnerText = entry.Value;
    body.AppendChild(keyNode); //close TAB

    //Write to xmml verdion 2: (uncomment the next 4 lines and comment the above 3 - version 1
    //XmlElement key = xmlDoc.CreateElement(string.Empty, entry.Key, string.Empty);
    //XmlText value = xmlDoc.CreateTextNode(entry.Value);
    //key.AppendChild(value);
    //body.AppendChild(key);
}

Both versions (1 and 2 inside foreach loop) give the output:

<?xml version="1.0" encoding="UTF-8"?>
<body>
    <level1>
        <level2>text</level2>
        <level2>ther text</level2>
         <same_level2>more text</same_level2>
    </level1>
</body>

(Note: third line "same level2" in dictionary can be also level2 as the others but I wanted to ilustrate the advantage of the dictionary - in my case I needed level2 with different names.

How to force a checkbox and text on the same line?

You can wrap the label around the input:

 **<label for="a"><input type="checkbox" id="a">a</label>**

This worked for me.

Python decorators in classes

Declare in inner class. This solution is pretty solid and recommended.

class Test(object):
    class Decorators(object):
    @staticmethod
    def decorator(foo):
        def magic(self, *args, **kwargs) :
            print("start magic")
            foo(self, *args, **kwargs)
            print("end magic")
        return magic

    @Decorators.decorator
    def bar( self ) :
        print("normal call")

test = Test()

test.bar()

The result:

>>> test = Test()
>>> test.bar()
start magic
normal call
end magic
>>> 

Filter Pyspark dataframe column with None value

Try to just use isNotNull function.

df.filter(df.dt_mvmt.isNotNull()).count()

ALTER TABLE DROP COLUMN failed because one or more objects access this column

I had the same problem and this was the script that worked for me with a table with a two part name separated by a period ".".

USE [DATABASENAME] GO ALTER TABLE [TableNamePart1].[TableNamePart2] DROP CONSTRAINT [DF__ TableNamePart1D__ColumnName__5AEE82B9] GO ALTER TABLE [TableNamePart1].[ TableNamePart1] DROP COLUMN [ColumnName] GO

Can I compile all .cpp files in src/ to .o's in obj/, then link to binary in ./?

Wildcard works for me also, but I'd like to give a side note for those using directory variables. Always use slash for folder tree (not backslash), otherwise it will fail:

BASEDIR = ../..
SRCDIR = $(BASEDIR)/src
INSTALLDIR = $(BASEDIR)/lib

MODULES = $(wildcard $(SRCDIR)/*.cpp)
OBJS = $(wildcard *.o)

How do you change the width and height of Twitter Bootstrap's tooltips?

I realize this is a very old question, but if I landed here, so will others. So I figured I weigh in.

If you want the tooltip to be responsive to one line only regardless of how much content you add to it, the width has to be flexible. However, Bootstrap does initiate the tooltip to a width, so you have to at least declare what that width will be and make it flexible from that size on up. This is what I recommend:

.tooltip-inner {
    min-width: 100px;
    max-width: 100%; 
}

The min-width declares a starting size. As opposed to the max-width, as some other would suggest, which it declares a stopping width. According to your question, you shouldn't declare a final width or your tooltip content will eventually wrap at that point. Instead, you use an infinite width or flexible width. max-width: 100%; will ensure that once the tooltip has initiated at 100px wide, it will grow and adjust to your content regardless of the amount of content you have in it.

KEEP IN MIND Tooltips are not intended to carry a lot of content. It could look funky if you had a long string across the entire screen. And it will definitely will have an impact in your responsive views, specially smartphone (320px width).

I would recommend two solutions to perfect this:

  1. Keep your tooltip content to a minimum so as to not exceed 320px wide. And even if you do this you must remember if you have the tooltip placed at the right of the screen and with data-placement:right, your tooltip content will not be visible in smartphones (hence why bootstrap initially designed them to be responsive to its content and allow it to wrap)
  2. If you are hellbent on using this one line tooltip concept, then cover your six by using a @media query to reset your tooltip to fit the smartphone view. Like this:

My demo HERE demonstrates the flexibility and responsiveness on the tooltips according to content size and device display size as well

@media (max-width: 320px) {
    .tooltip-inner {
         min-width: initial;
         width: 320px;
    }
}

Style bottom Line in Android

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:top="-6dp"
        android:left="-6dp"
        android:right="-6dp"
        android:bottom="0dp">

        <shape android:shape="rectangle">
            <solid android:color="#88FFFF00"/>
            <stroke
                android:width="5dp"
                android:color="#FF000000"/>
        </shape>
    </item>
</layer-list>

How to set a header for a HTTP GET request, and trigger file download?

i want to post my solution here which was done AngularJS, ASP.NET MVC. The code illustrates how to download file with authentication.

WebApi method along with helper class:

[RoutePrefix("filess")]
class FileController: ApiController
{
    [HttpGet]
    [Route("download-file")]
    [Authorize(Roles = "admin")]
    public HttpResponseMessage DownloadDocument([FromUri] int fileId)
    {
        var file = "someFile.docx"// asking storage service to get file path with id
        return Request.ReturnFile(file);
    }
}

static class DownloadFIleFromServerHelper
{
    public static HttpResponseMessage ReturnFile(this HttpRequestMessage request, string file)
    {
        var result = request.CreateResponse(HttpStatusCode.OK);

        result.Content = new StreamContent(new FileStream(file, FileMode.Open, FileAccess.Read));
        result.Content.Headers.Add("x-filename", Path.GetFileName(file)); // letters of header names will be lowercased anyway in JS.
        result.Content.Headers.ContentType = new MediaTypeHeaderValue("application/octet-stream");
        result.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
        {
            FileName = Path.GetFileName(file)
        };

        return result;
    }
}

Web.config file changes to allow sending file name in custom header.

<configuration>
    <system.webServer>
        <httpProtocol>
            <customHeaders>
                <add name="Access-Control-Allow-Methods" value="POST,GET,PUT,PATCH,DELETE,OPTIONS" />
                <add name="Access-Control-Allow-Headers" value="Authorization,Content-Type,x-filename" />
                <add name="Access-Control-Expose-Headers" value="Authorization,Content-Type,x-filename" />
                <add name="Access-Control-Allow-Origin" value="*" />

Angular JS Service Part:

function proposalService($http, $cookies, config, FileSaver) {
        return {
                downloadDocument: downloadDocument
        };

    function downloadFile(documentId, errorCallback) {
    $http({
        url: config.apiUrl + "files/download-file?documentId=" + documentId,
        method: "GET",
        headers: {
            "Content-type": "application/json; charset=utf-8",
            "Authorization": "Bearer " + $cookies.get("api_key")
        },
        responseType: "arraybuffer"  
        })
    .success( function(data, status, headers) {
        var filename = headers()['x-filename'];

        var blob = new Blob([data], { type: "application/octet-binary" });
        FileSaver.saveAs(blob, filename);
    })
    .error(function(data, status) {
        console.log("Request failed with status: " + status);
        errorCallback(data, status);
    });
};
};

Module dependency for FileUpload: angular-file-download (gulp install angular-file-download --save). Registration looks like below.

var app = angular.module('cool',
[
    ...
    require('angular-file-saver'),
])
. // other staff.

Is it possible to set ENV variables for rails development environment in my code?

As an aside to the solutions here, there are cleaner alternatives if you're using certain development servers.

With Heroku's Foreman, you can create per-project environment variables in a .env file:

ADMIN_PASSOWRD="secret"

With Pow, you can use a .powenv file:

export ADMIN_PASSOWRD="secret"

Android: How to add R.raw to project?

Try putting a + before R.xyz. That should start showing additional folders, e.g.:

+ R.raw.beep.mp3

Warning: Attempt to present * on * whose view is not in the window hierarchy - swift

Swift 5.1:

let storyboard = UIStoryboard.init(name: "Main", bundle: Bundle.main)
let mainViewController = storyboard.instantiateViewController(withIdentifier: "ID")
let appDeleg = UIApplication.shared.delegate as! AppDelegate
let root = appDeleg.window?.rootViewController as! UINavigationController
root.pushViewController(mainViewController, animated: true)

How to paste into a terminal?

Gnome terminal defaults to ControlShiftv

OSX terminal defaults to Commandv. You can also use CommandControlv to paste the text in escaped form.

Windows 7 terminal defaults to CtrlShiftInsert

I/O error(socket error): [Errno 111] Connection refused

I previously had this problem with my EC2 instance (I was serving couchdb to serve resources -- am considering Amazon's S3 for the future).

One thing to check (assuming Ec2) is that the couchdb port is added to your open ports within your security policy.

I specifically encountered

"[Errno 111] Connection refused"

over EC2 when the instance was stopped and started. The problem seems to be a pidfile race. The solution for me was killing couchdb (entirely and properly) via:

pkill -f couchdb

and then restarting with:

/etc/init.d/couchdb restart

How to use GOOGLEFINANCE(("CURRENCY:EURAUD")) function

Bear in mind that the GoogleFinance() function isn't working 100% in the new version of Google Sheets. For example, converting from USD to GBP using the formula GoogleFinance("CURRENCY:USDGBP") gives 0.603974 in the old version, but only 0.6 in the new one. Looks like there's a rounding error.

Optimal number of threads per core

Benchmark.

I'd start ramping up the number of threads for an application, starting at 1, and then go to something like 100, run three-five trials for each number of threads, and build yourself a graph of operation speed vs. number of threads.

You should that the four thread case is optimal, with slight rises in runtime after that, but maybe not. It may be that your application is bandwidth limited, ie, the dataset you're loading into memory is huge, you're getting lots of cache misses, etc, such that 2 threads are optimal.

You can't know until you test.

How can I round a number in JavaScript? .toFixed() returns a string?

You can simply use a '+' to convert the result to a number.

var x = 22.032423;
x = +x.toFixed(2); // x = 22.03

System.currentTimeMillis() vs. new Date() vs. Calendar.getInstance().getTime()

Looking at the JDK, innermost constructor for Calendar.getInstance() has this:

public GregorianCalendar(TimeZone zone, Locale aLocale) {
    super(zone, aLocale);
    gdate = (BaseCalendar.Date) gcal.newCalendarDate(zone);
    setTimeInMillis(System.currentTimeMillis());
}

so it already automatically does what you suggest. Date's default constructor holds this:

public Date() {
    this(System.currentTimeMillis());
}

So there really isn't need to get system time specifically unless you want to do some math with it before creating your Calendar/Date object with it. Also I do have to recommend joda-time to use as replacement for Java's own calendar/date classes if your purpose is to work with date calculations a lot.

How to yum install Node.JS on Amazon Linux

I had Node.js 6.x installed and wanted to install Node.js 8.x.

Here's the commands I used (taken from Nodejs's site with a few extra steps to handle the yum cached data):

  1. sudo yum remove nodejs: Uninstall Node.js 6.x (I don't know if this was necessary or not)
  2. curl --silent --location https://rpm.nodesource.com/setup_8.x | sudo bash -
  3. sudo yum clean all
  4. sudo yum makecache: Regenerate metadata cache (this wasn't in the docs, but yum kept trying to install Node.jx 6.x, unsuccessfully, until I issued these last two commands)
  5. sudo yum install nodejs: Install Node.js 8.x

Using Linq to get the last N elements of a collection?

Honestly I'm not super proud of the answer, but for small collections you could use the following:

var lastN = collection.Reverse().Take(n).Reverse();

A bit hacky but it does the job ;)

Install a .NET windows service without InstallUtil.exe

The above examples didn't really work for me, and the link to the forum as a #1 solution is awful to dig through. Here is a class I wrote (in part), and the other bit is merged from this link I found buried somewhere

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

using System.ServiceProcess;
using System.Runtime.InteropServices;

namespace SystemControl {
    class Services {

#region "Environment Variables"
        public static string GetEnvironment(string name, bool ExpandVariables=true) {
            if ( ExpandVariables ) {
                return System.Environment.GetEnvironmentVariable( name );
            } else {
                return (string)Microsoft.Win32.Registry.LocalMachine.OpenSubKey( @"SYSTEM\CurrentControlSet\Control\Session Manager\Environment\" ).GetValue( name, "", Microsoft.Win32.RegistryValueOptions.DoNotExpandEnvironmentNames );
            }
        }

        public static void SetEnvironment( string name, string value ) {
            System.Environment.SetEnvironmentVariable(name, value);
        }
#endregion

#region "ServiceCalls Native"
        public static ServiceController[] List { get { return ServiceController.GetServices(); } }

        public static void Start( string serviceName, int timeoutMilliseconds ) {
            ServiceController service=new ServiceController( serviceName );
            try {
                TimeSpan timeout=TimeSpan.FromMilliseconds( timeoutMilliseconds );

                service.Start();
                service.WaitForStatus( ServiceControllerStatus.Running, timeout );
            } catch {
                // ...
            }
        }

        public static void Stop( string serviceName, int timeoutMilliseconds ) {
            ServiceController service=new ServiceController( serviceName );
            try {
                TimeSpan timeout=TimeSpan.FromMilliseconds( timeoutMilliseconds );

                service.Stop();
                service.WaitForStatus( ServiceControllerStatus.Stopped, timeout );
            } catch {
                // ...
            }
        }

        public static void Restart( string serviceName, int timeoutMilliseconds ) {
            ServiceController service=new ServiceController( serviceName );
            try {
                int millisec1=Environment.TickCount;
                TimeSpan timeout=TimeSpan.FromMilliseconds( timeoutMilliseconds );

                service.Stop();
                service.WaitForStatus( ServiceControllerStatus.Stopped, timeout );

                // count the rest of the timeout
                int millisec2=Environment.TickCount;
                timeout=TimeSpan.FromMilliseconds( timeoutMilliseconds-( millisec2-millisec1 ) );

                service.Start();
                service.WaitForStatus( ServiceControllerStatus.Running, timeout );
            } catch {
                // ...
            }
        }

        public static bool IsInstalled( string serviceName ) {
            // get list of Windows services
            ServiceController[] services=ServiceController.GetServices();

            // try to find service name
            foreach ( ServiceController service in services ) {
                if ( service.ServiceName==serviceName )
                    return true;
            }
            return false;
        }
#endregion

#region "ServiceCalls API"
        private const int STANDARD_RIGHTS_REQUIRED = 0xF0000;
        private const int SERVICE_WIN32_OWN_PROCESS = 0x00000010;

        [Flags]
        public enum ServiceManagerRights {
            Connect = 0x0001,
            CreateService = 0x0002,
            EnumerateService = 0x0004,
            Lock = 0x0008,
            QueryLockStatus = 0x0010,
            ModifyBootConfig = 0x0020,
            StandardRightsRequired = 0xF0000,
            AllAccess = (StandardRightsRequired | Connect | CreateService |
            EnumerateService | Lock | QueryLockStatus | ModifyBootConfig)
        }

        [Flags]
        public enum ServiceRights {
            QueryConfig = 0x1,
            ChangeConfig = 0x2,
            QueryStatus = 0x4,
            EnumerateDependants = 0x8,
            Start = 0x10,
            Stop = 0x20,
            PauseContinue = 0x40,
            Interrogate = 0x80,
            UserDefinedControl = 0x100,
            Delete = 0x00010000,
            StandardRightsRequired = 0xF0000,
            AllAccess = (StandardRightsRequired | QueryConfig | ChangeConfig |
            QueryStatus | EnumerateDependants | Start | Stop | PauseContinue |
            Interrogate | UserDefinedControl)
        }

        public enum ServiceBootFlag {
            Start = 0x00000000,
            SystemStart = 0x00000001,
            AutoStart = 0x00000002,
            DemandStart = 0x00000003,
            Disabled = 0x00000004
        }

        public enum ServiceState {
            Unknown = -1, // The state cannot be (has not been) retrieved.
            NotFound = 0, // The service is not known on the host server.
            Stop = 1, // The service is NET stopped.
            Run = 2, // The service is NET started.
            Stopping = 3,
            Starting = 4,
        }

        public enum ServiceControl {
            Stop = 0x00000001,
            Pause = 0x00000002,
            Continue = 0x00000003,
            Interrogate = 0x00000004,
            Shutdown = 0x00000005,
            ParamChange = 0x00000006,
            NetBindAdd = 0x00000007,
            NetBindRemove = 0x00000008,
            NetBindEnable = 0x00000009,
            NetBindDisable = 0x0000000A
        }

        public enum ServiceError {
            Ignore = 0x00000000,
            Normal = 0x00000001,
            Severe = 0x00000002,
            Critical = 0x00000003
        }

        [StructLayout(LayoutKind.Sequential)]
        private class SERVICE_STATUS {
            public int dwServiceType = 0;
            public ServiceState dwCurrentState = 0;
            public int dwControlsAccepted = 0;
            public int dwWin32ExitCode = 0;
            public int dwServiceSpecificExitCode = 0;
            public int dwCheckPoint = 0;
            public int dwWaitHint = 0;
        }

        [DllImport("advapi32.dll", EntryPoint = "OpenSCManagerA")]
        private static extern IntPtr OpenSCManager(string lpMachineName, string lpDatabaseName, ServiceManagerRights dwDesiredAccess);
        [DllImport("advapi32.dll", EntryPoint = "OpenServiceA", CharSet = CharSet.Ansi)]
        private static extern IntPtr OpenService(IntPtr hSCManager, string lpServiceName, ServiceRights dwDesiredAccess);
        [DllImport("advapi32.dll", EntryPoint = "CreateServiceA")]
        private static extern IntPtr CreateService(IntPtr hSCManager, string lpServiceName, string lpDisplayName, ServiceRights dwDesiredAccess, int dwServiceType, ServiceBootFlag dwStartType, ServiceError dwErrorControl, string lpBinaryPathName, string lpLoadOrderGroup, IntPtr lpdwTagId, string lpDependencies, string lp, string lpPassword);
        [DllImport("advapi32.dll")]
        private static extern int CloseServiceHandle(IntPtr hSCObject);
        [DllImport("advapi32.dll")]
        private static extern int QueryServiceStatus(IntPtr hService, SERVICE_STATUS lpServiceStatus);
        [DllImport("advapi32.dll", SetLastError = true)]
        private static extern int DeleteService(IntPtr hService);
        [DllImport("advapi32.dll")]
        private static extern int ControlService(IntPtr hService, ServiceControl dwControl, SERVICE_STATUS lpServiceStatus);
        [DllImport("advapi32.dll", EntryPoint = "StartServiceA")]
        private static extern int StartService(IntPtr hService, int dwNumServiceArgs, int lpServiceArgVectors);

        /// <summary>
        /// Takes a service name and tries to stop and then uninstall the windows serviceError
        /// </summary>
        /// <param name="ServiceName">The windows service name to uninstall</param>
        public static void Uninstall(string ServiceName)
        {
            IntPtr scman = OpenSCManager(ServiceManagerRights.Connect);
            try
            {
                IntPtr service = OpenService(scman, ServiceName, ServiceRights.StandardRightsRequired | ServiceRights.Stop | ServiceRights.QueryStatus);
                if (service == IntPtr.Zero)
                {
                    throw new ApplicationException("Service not installed.");
                }
                try
                {
                    StopService(service);
                    int ret = DeleteService(service);
                    if (ret == 0)
                    {
                        int error = Marshal.GetLastWin32Error();
                        throw new ApplicationException("Could not delete service " + error);
                    }
                }
                finally
                {
                    CloseServiceHandle(service);
                }
            }
            finally
            {
                CloseServiceHandle(scman);
            }
        }

        /// <summary>
        /// Accepts a service name and returns true if the service with that service name exists
        /// </summary>
        /// <param name="ServiceName">The service name that we will check for existence</param>
        /// <returns>True if that service exists false otherwise</returns>
        public static bool ServiceIsInstalled(string ServiceName)
        {
            IntPtr scman = OpenSCManager(ServiceManagerRights.Connect);
            try
            {
                IntPtr service = OpenService(scman, ServiceName,
                ServiceRights.QueryStatus);
                if (service == IntPtr.Zero) return false;
                CloseServiceHandle(service);
                return true;
            }
            finally
            {
                CloseServiceHandle(scman);
            }
        }

        /// <summary>
        /// Takes a service name, a service display name and the path to the service executable and installs / starts the windows service.
        /// </summary>
        /// <param name="ServiceName">The service name that this service will have</param>
        /// <param name="DisplayName">The display name that this service will have</param>
        /// <param name="FileName">The path to the executable of the service</param>
        public static void InstallAndStart(string ServiceName, string DisplayName,
        string FileName)
        {
            IntPtr scman = OpenSCManager(ServiceManagerRights.Connect |
            ServiceManagerRights.CreateService);
            try
            {
                IntPtr service = OpenService(scman, ServiceName,
                ServiceRights.QueryStatus | ServiceRights.Start);
                if (service == IntPtr.Zero)
                {
                    service = CreateService(scman, ServiceName, DisplayName,
                    ServiceRights.QueryStatus | ServiceRights.Start, SERVICE_WIN32_OWN_PROCESS,
                    ServiceBootFlag.AutoStart, ServiceError.Normal, FileName, null, IntPtr.Zero,
                    null, null, null);
                }
                if (service == IntPtr.Zero)
                {
                    throw new ApplicationException("Failed to install service.");
                }
                try
                {
                    StartService(service);
                }
                finally
                {
                    CloseServiceHandle(service);
                }
            }
            finally
            {
                CloseServiceHandle(scman);
            }
        }

        /// <summary>
        /// Takes a service name and starts it
        /// </summary>
        /// <param name="Name">The service name</param>
        public static void StartService(string Name)
        {
            IntPtr scman = OpenSCManager(ServiceManagerRights.Connect);
            try
            {
                IntPtr hService = OpenService(scman, Name, ServiceRights.QueryStatus |
                ServiceRights.Start);
                if (hService == IntPtr.Zero)
                {
                    throw new ApplicationException("Could not open service.");
                }
                try
                {
                    StartService(hService);
                }
                finally
                {
                    CloseServiceHandle(hService);
                }
            }
            finally
            {
                CloseServiceHandle(scman);
            }
        }

        /// <summary>
        /// Stops the provided windows service
        /// </summary>
        /// <param name="Name">The service name that will be stopped</param>
        public static void StopService(string Name)
        {
            IntPtr scman = OpenSCManager(ServiceManagerRights.Connect);
            try
            {
                IntPtr hService = OpenService(scman, Name, ServiceRights.QueryStatus |
                ServiceRights.Stop);
                if (hService == IntPtr.Zero)
                {
                    throw new ApplicationException("Could not open service.");
                }
                try
                {
                    StopService(hService);
                }
                finally
                {
                    CloseServiceHandle(hService);
                }
            }
            finally
            {
                CloseServiceHandle(scman);
            }
        }

        /// <summary>
        /// Stars the provided windows service
        /// </summary>
        /// <param name="hService">The handle to the windows service</param>
        private static void StartService(IntPtr hService)
        {
            SERVICE_STATUS status = new SERVICE_STATUS();
            StartService(hService, 0, 0);
            WaitForServiceStatus(hService, ServiceState.Starting, ServiceState.Run);
        }

        /// <summary>
        /// Stops the provided windows service
        /// </summary>
        /// <param name="hService">The handle to the windows service</param>
        private static void StopService(IntPtr hService)
        {
            SERVICE_STATUS status = new SERVICE_STATUS();
            ControlService(hService, ServiceControl.Stop, status);
            WaitForServiceStatus(hService, ServiceState.Stopping, ServiceState.Stop);
        }

        /// <summary>
        /// Takes a service name and returns the <code>ServiceState</code> of the corresponding service
        /// </summary>
        /// <param name="ServiceName">The service name that we will check for his <code>ServiceState</code></param>
        /// <returns>The ServiceState of the service we wanted to check</returns>
        public static ServiceState GetServiceStatus(string ServiceName)
        {
            IntPtr scman = OpenSCManager(ServiceManagerRights.Connect);
            try
            {
                IntPtr hService = OpenService(scman, ServiceName,
                ServiceRights.QueryStatus);
                if (hService == IntPtr.Zero)
                {
                    return ServiceState.NotFound;
                }
                try
                {
                    return GetServiceStatus(hService);
                }
                finally
                {
                    CloseServiceHandle(scman);
                }
            }
            finally
            {
                CloseServiceHandle(scman);
            }
        }

        /// <summary>
        /// Gets the service state by using the handle of the provided windows service
        /// </summary>
        /// <param name="hService">The handle to the service</param>
        /// <returns>The <code>ServiceState</code> of the service</returns>
        private static ServiceState GetServiceStatus(IntPtr hService)
        {
            SERVICE_STATUS ssStatus = new SERVICE_STATUS();
            if (QueryServiceStatus(hService, ssStatus) == 0)
            {
                throw new ApplicationException("Failed to query service status.");
            }
            return ssStatus.dwCurrentState;
        }

        /// <summary>
        /// Returns true when the service status has been changes from wait status to desired status
        /// ,this method waits around 10 seconds for this operation.
        /// </summary>
        /// <param name="hService">The handle to the service</param>
        /// <param name="WaitStatus">The current state of the service</param>
        /// <param name="DesiredStatus">The desired state of the service</param>
        /// <returns>bool if the service has successfully changed states within the allowed timeline</returns>
        private static bool WaitForServiceStatus(IntPtr hService, ServiceState
        WaitStatus, ServiceState DesiredStatus)
        {
            SERVICE_STATUS ssStatus = new SERVICE_STATUS();
            int dwOldCheckPoint;
            int dwStartTickCount;

            QueryServiceStatus(hService, ssStatus);
            if (ssStatus.dwCurrentState == DesiredStatus) return true;
            dwStartTickCount = Environment.TickCount;
            dwOldCheckPoint = ssStatus.dwCheckPoint;

            while (ssStatus.dwCurrentState == WaitStatus)
            {
                // Do not wait longer than the wait hint. A good interval is
                // one tenth the wait hint, but no less than 1 second and no
                // more than 10 seconds.

                int dwWaitTime = ssStatus.dwWaitHint / 10;

                if (dwWaitTime < 1000) dwWaitTime = 1000;
                else if (dwWaitTime > 10000) dwWaitTime = 10000;

                System.Threading.Thread.Sleep(dwWaitTime);

                // Check the status again.

                if (QueryServiceStatus(hService, ssStatus) == 0) break;

                if (ssStatus.dwCheckPoint > dwOldCheckPoint)
                {
                    // The service is making progress.
                    dwStartTickCount = Environment.TickCount;
                    dwOldCheckPoint = ssStatus.dwCheckPoint;
                }
                else
                {
                    if (Environment.TickCount - dwStartTickCount > ssStatus.dwWaitHint)
                    {
                        // No progress made within the wait hint
                        break;
                    }
                }
            }
            return (ssStatus.dwCurrentState == DesiredStatus);
        }

        /// <summary>
        /// Opens the service manager
        /// </summary>
        /// <param name="Rights">The service manager rights</param>
        /// <returns>the handle to the service manager</returns>
        private static IntPtr OpenSCManager(ServiceManagerRights Rights)
        {
            IntPtr scman = OpenSCManager(null, null, Rights);
            if (scman == IntPtr.Zero)
            {
                throw new ApplicationException("Could not connect to service control manager.");
            }
            return scman;
        }

#endregion

    }
}

To install a service, run the InstallAndStart command as follows:

  SystemControl.InstallAndStart(
                                 "apache",
                                 "Apache Web Server",
                                 @"""c:\apache\bin\httpd.exe"" -k runservice"
  );

Make sure the account that is running the program has permission to install services. You can always 'Run As Administrator' on the program.

I have also included several commands for non-api access which do not install or remove services, but you can list them and control several (start, stop, restart). You really only need to elevate permissions for installing or removing services.

There are a couple of commands for getting and setting environment variables as well, such as OPENSSL_CONF or TEMP. For the most part, the parameters and method names should be pretty self-explanatory.

Does WhatsApp offer an open API?

WhatsApp does not have a API available for public use. As you put it, it's a closed system.

However, they provide several other ways in which your iPhone application can interact with WhatsApp: through custom URL schemes, share extension and through the Document Interaction API.

See this WhatsApp FAQ article.

How to implement HorizontalScrollView like Gallery?

I implemented something similar with Horizontal Variable ListView The only drawback is, it works only with Android 2.3 and later.

Using this library is as simple as implementing a ListView with a corresponding Adapter. The library also provides an example

When should you NOT use a Rules Engine?

I'm a big fan of Business Rules Engines, since it can help you make your life much easier as a programmer. One of the first experiences I've had while working on a Data Warehouse project was to find Stored Procedures containing complicated CASE structures stretching over entire pages. It was a nightmare to debug, since it was very difficult to understand the logic applied in such long CASE structures, and to determine if you have an overlapping between a rule at page 1 of the code and another from page 5. Overall, we had more than 300 such rules embedded in the code.

When we've received a new development requirement, for something called Accounting Destination, which was involving treating more than 3000 rules, i knew something had to change. Back then I've been working on a prototype which later on become the parent of what now is a Custom Business Rule engine, capable of handling all SQL standard operators. Initially we've been using Excel as an authoring tool and , later on, we've created an ASP.net application which will allow the Business Users to define their own business rules, without the need of writing code. Now the system works fine, with very few bugs, and contains over 7000 rules for calculating this Accounting Destination. I don't think such scenario would have been possible by just hard-coding. And the users are pretty happy that they can define their own rules without IT becoming their bottleneck.

Still, there are limits to such approach:

  • You need to have capable business users which have an excellent understanding of the company business.
  • There is a significant workload on searching the entire system (in our case a Data Warehouse), in order to determine all hard-coded conditions which make sense to translate into rules to be handled by a Business Rule Engine. We've also had to take good care that these initial templates to be fully understandable by Business Users.
  • You need to have an application used for rules authoring, in which algorithms for detection of overlapping business rules is implemented. Otherwise you'll end up with a big mess, where no one understands anymore the results they get. When you have a bug in a generic component like a Custom Business Rule Engine, it can be very difficult to debug and involve extensive tests to make sure that things that worked before also work now.

More details on this topic can be found on a post I've written: http://dwhbp.com/post/2011/10/30/Implementing-a-Business-Rule-Engine.aspx

Overall, the biggest advantage of using a Business Rule Engines is that it allows the users to take back control over the Business Rule definitions and authoring, without the need of going to the IT department each time they need to modify something. It also the reduces the workload over IT development teams, which can now focus on building stuff with more added value.

Cheers,

Nicolae

CSS3 gradient background set on body doesn't stretch but instead repeats?

Dirty; maybe could you just add a min-height: 100%; to the html, and body tags? That or at least set a default background color that is the end gradient color as well.

What database does Google use?

Bigtable

A Distributed Storage System for Structured Data

Bigtable is a distributed storage system (built by Google) for managing structured data that is designed to scale to a very large size: petabytes of data across thousands of commodity servers.

Many projects at Google store data in Bigtable, including web indexing, Google Earth, and Google Finance. These applications place very different demands on Bigtable, both in terms of data size (from URLs to web pages to satellite imagery) and latency requirements (from backend bulk processing to real-time data serving).

Despite these varied demands, Bigtable has successfully provided a flexible, high-performance solution for all of these Google products.

Some features

  • fast and extremely large-scale DBMS
  • a sparse, distributed multi-dimensional sorted map, sharing characteristics of both row-oriented and column-oriented databases.
  • designed to scale into the petabyte range
  • it works across hundreds or thousands of machines
  • it is easy to add more machines to the system and automatically start taking advantage of those resources without any reconfiguration
  • each table has multiple dimensions (one of which is a field for time, allowing versioning)
  • tables are optimized for GFS (Google File System) by being split into multiple tablets - segments of the table as split along a row chosen such that the tablet will be ~200 megabytes in size.

Architecture

BigTable is not a relational database. It does not support joins nor does it support rich SQL-like queries. Each table is a multidimensional sparse map. Tables consist of rows and columns, and each cell has a time stamp. There can be multiple versions of a cell with different time stamps. The time stamp allows for operations such as "select 'n' versions of this Web page" or "delete cells that are older than a specific date/time."

In order to manage the huge tables, Bigtable splits tables at row boundaries and saves them as tablets. A tablet is around 200 MB, and each machine saves about 100 tablets. This setup allows tablets from a single table to be spread among many servers. It also allows for fine-grained load balancing. If one table is receiving many queries, it can shed other tablets or move the busy table to another machine that is not so busy. Also, if a machine goes down, a tablet may be spread across many other servers so that the performance impact on any given machine is minimal.

Tables are stored as immutable SSTables and a tail of logs (one log per machine). When a machine runs out of system memory, it compresses some tablets using Google proprietary compression techniques (BMDiff and Zippy). Minor compactions involve only a few tablets, while major compactions involve the whole table system and recover hard-disk space.

The locations of Bigtable tablets are stored in cells. The lookup of any particular tablet is handled by a three-tiered system. The clients get a point to a META0 table, of which there is only one. The META0 table keeps track of many META1 tablets that contain the locations of the tablets being looked up. Both META0 and META1 make heavy use of pre-fetching and caching to minimize bottlenecks in the system.

Implementation

BigTable is built on Google File System (GFS), which is used as a backing store for log and data files. GFS provides reliable storage for SSTables, a Google-proprietary file format used to persist table data.

Another service that BigTable makes heavy use of is Chubby, a highly-available, reliable distributed lock service. Chubby allows clients to take a lock, possibly associating it with some metadata, which it can renew by sending keep alive messages back to Chubby. The locks are stored in a filesystem-like hierarchical naming structure.

There are three primary server types of interest in the Bigtable system:

  1. Master servers: assign tablets to tablet servers, keeps track of where tablets are located and redistributes tasks as needed.
  2. Tablet servers: handle read/write requests for tablets and split tablets when they exceed size limits (usually 100MB - 200MB). If a tablet server fails, then a 100 tablet servers each pickup 1 new tablet and the system recovers.
  3. Lock servers: instances of the Chubby distributed lock service. Lots of actions within BigTable require acquisition of locks including opening tablets for writing, ensuring that there is no more than one active Master at a time, and access control checking.

Example from Google's research paper:

alt text

A slice of an example table that stores Web pages. The row name is a reversed URL. The contents column family contains the page contents, and the anchor column family contains the text of any anchors that reference the page. CNN's home page is referenced by both the Sports Illustrated and the MY-look home pages, so the row contains columns named anchor:cnnsi.com and anchor:my.look.ca. Each anchor cell has one version; the contents column has three versions, at timestamps t3, t5, and t6.

API

Typical operations to BigTable are creation and deletion of tables and column families, writing data and deleting columns from a row. BigTable provides this functions to application developers in an API. Transactions are supported at the row level, but not across several row keys.


Here is the link to the PDF of the research paper.

And here you can find a video showing Google's Jeff Dean in a lecture at the University of Washington, discussing the Bigtable content storage system used in Google's backend.

Is there any 'out-of-the-box' 2D/3D plotting library for C++?

I found the game library Allegro easy to use back in the day. Might be worth a look.

How to find the path of the local git repository when I am possibly in a subdirectory

git rev-parse --show-toplevel

could be enough if executed within a git repo.
From git rev-parse man page:

--show-toplevel

Show the absolute path of the top-level directory.

For older versions (before 1.7.x), the other options are listed in "Is there a way to get the git root directory in one command?":

git rev-parse --git-dir

That would give the path of the .git directory.


The OP mentions:

git rev-parse --show-prefix

which returns the local path under the git repo root. (empty if you are at the git repo root)


Note: for simply checking if one is in a git repo, I find the following command quite expressive:

git rev-parse --is-inside-work-tree

And yes, if you need to check if you are in a .git git-dir folder:

git rev-parse --is-inside-git-dir

How to place a JButton at a desired location in a JFrame using Java

Define somewhere the consts :

private static final int BUTTON_LOCATION_X = 300;  // location x 
private static final int BUTTON_LOCATION_Y = 50;   // location y 
private static final int BUTTON_SIZE_X = 140;      // size height
private static final int BUTTON_SIZE_Y = 50;       // size width

and then below :

                JButton startButton = new JButton("Click Me To Start!");
                // startButton.setBounds(300, 50,140, 50 );
                startButton.setBounds(BUTTON_LOCATION_X
                                    , BUTTON_LOCATION_Y,
                                      BUTTON_SIZE_X, 
                                      BUTTON_SIZE_Y );
                contentPane.add(startButton);

where contentPane is the Container object that holds the entire frame :

 JFrame frame = new JFrame("Some name goes here");
 Container contentPane = frame.getContentPane();

I hope this helps , works great for me ...

SQL Server : fetching records between two dates?

As others have answered, you probably have a DATETIME (or other variation) column and not a DATE datatype.

Here's a condition that works for all, including DATE:

SELECT * 
FROM xxx 
WHERE dates >= '20121026' 
  AND dates <  '20121028'    --- one day after 
                             --- it is converted to '2012-10-28 00:00:00.000'
 ;

@Aaron Bertrand has blogged about this at: What do BETWEEN and the devil have in common?

How to use basic authorization in PHP curl

Try the following code :

$username='ABC';
$password='XYZ';
$URL='<URL>';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL,$URL);
curl_setopt($ch, CURLOPT_TIMEOUT, 30); //timeout after 30 seconds
curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
curl_setopt($ch, CURLOPT_USERPWD, "$username:$password");
$result=curl_exec ($ch);
$status_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);   //get status code
curl_close ($ch);

How to get text with Selenium WebDriver in Python

The answer is:

driver.find_element_by_class_name("ctsymbol").text

Why is document.write considered a "bad practice"?

Browser Violation

.write is considered a browser violation as it halts the parser from rendering the page. The parser receives the message that the document is being modified; hence, it gets blocked until JS has completed its process. Only at this time will the parser resume.

Performance

The biggest consequence of employing such a method is lowered performance. The browser will take longer to load page content. The adverse reaction on load time depends on what is being written to the document. You won't see much of a difference if you are adding a <p> tag to the DOM as opposed to passing an array of 50-some references to JavaScript libraries (something which I have seen in working code and resulted in an 11 second delay - of course, this also depends on your hardware).

All in all, it's best to steer clear of this method if you can help it.

For more info see Intervening against document.write()

Find Facebook user (url to profile page) by known email address

Andreas, I've also been looking for an "email-to-id" ellegant solution and couldn't find one. However, as you said, screen scraping is not such a bad idea in this case, because emails are unique and you either get a single match or none. As long as Facebook don't change their search page drastically, the following will do the trick:

final static String USER_SEARCH_QUERY = "http://www.facebook.com/search.php?init=s:email&q=%s&type=users";
final static String USER_URL_PREFIX = "http://www.facebook.com/profile.php?id=";

public static String emailToID(String email)
{
    try
    {
        String html = getHTML(String.format(USER_SEARCH_QUERY, email));
        if (html != null)
        {
            int i = html.indexOf(USER_URL_PREFIX) + USER_URL_PREFIX.length();
            if (i > 0)
            {
                StringBuilder sb = new StringBuilder();
                char c;
                while (Character.isDigit(c = html.charAt(i++)))
                    sb.append(c);
                if (sb.length() > 0)
                    return sb.toString();
            }
        }
    } catch (Exception e)
    {
        e.printStackTrace();
    }
    return null;
}

private static String getHTML(String htmlUrl) throws MalformedURLException, IOException
{
    StringBuilder response = new StringBuilder();
    URL url = new URL(htmlUrl);
    HttpURLConnection httpConn = (HttpURLConnection) url.openConnection();
    httpConn.setRequestMethod("GET");
    if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK)
    {
        BufferedReader input = new BufferedReader(new InputStreamReader(httpConn.getInputStream()), 8192);
        String strLine = null;
        while ((strLine = input.readLine()) != null)
            response.append(strLine);
        input.close();
    }
    return (response.length() == 0) ? null : response.toString();
}

Python read next()

Using next or readlines etc, is not necessary. As the documentation says: "For reading lines from a file, you can loop over the file object. This is memory efficient, fast, and leads to simple code".

Here's an example:

with open('/path/to/file') as myfile:
    for line in myfile:
        print(line)

Get an element by index in jQuery

You could skip the jquery and just use CSS style tagging:

 <ul>
 <li>India</li>
 <li>Indonesia</li>
 <li style="background-color:#343434;">China</li>
 <li>United States</li>
 <li>United Kingdom</li>
 </ul>

Add text at the end of each line

Concise version of the sed command:

sed -i s/$/:80/ file.txt

Explanation:

  • sed stream editor
    • -i in-place (edit file in place)
    • s substitution command
    • /replacement_from_reg_exp/replacement_to_text/ statement
    • $ matches the end of line (replacement_from_reg_exp)
    • :80 text you want to add at the end of every line (replacement_to_text)
  • file.txt the file name

How to install xgboost in Anaconda Python (Windows platform)?

Open anaconda prompt and run

pip install xgboost

Finding the second highest number in array

import java.util.Scanner;

public class SecondHighestFromArrayTest {

public static void main(String[] args) {
    Scanner scan = new Scanner(System.in);
    System.out.println("Enter size of Array");
    int size = scan.nextInt();
    int[] arr = new int[size];
    for (int i = 0; i < size; i++) {
        arr[i] = scan.nextInt();
    }
    System.out.println("second highest element " + getSecondHighest(arr));
}

public static int getSecondHighest(int arr[]) {
    int firstHighest = arr[0];
    int secondHighest = arr[0];
    for (int i = 0; i < arr.length; i++) {
        if (arr[i] > firstHighest) {
            secondHighest = firstHighest;
            firstHighest = arr[i];
        } else if (arr[i] > secondHighest) {
            secondHighest = arr[i];
        }
    }
    return secondHighest;
}

}

DOUBLE vs DECIMAL in MySQL

"are there any issue we should expect from only storing and retreiving a money amount in a DOUBLE column ?"

It sounds like no rounding errors can be produced in your scenario and if there were, they would be truncated by the conversion to BigDecimal.

So I would say no.

However, there is no guarantee that some change in the future will not introduce a problem.

How to create dynamic href in react render function?

You can use ES6 backtick syntax too

<a href={`/customer/${item._id}`} >{item.get('firstName')} {item.get('lastName')}</a>

More info on es6 template literals

How to send SMS in Java

There are two ways : First : Use a SMS API Gateway which you need to pay for it , maybe you find some trial even free ones but it's scarce . Second : To use AT command with a modem GSM connected to your laptop . that's all

Create a tar.xz in one command

Try this: tar -cf file.tar file-to-compress ; xz -z file.tar

Note:

  1. tar.gz and tar.xz are not the same; xz provides better compression.
  2. Don't use pipe | because this runs commands simultaneously. Using ; or & executes commands one after another.

Most simple code to populate JTable from ResultSet

I think the simplest way to build a model from an instance of ResultSet, could be as follows.

public static void main(String[] args) throws Exception {
    // The Connection is obtained

    ResultSet rs = stmt.executeQuery("select * from product_info");

    // It creates and displays the table
    JTable table = new JTable(buildTableModel(rs));

    // Closes the Connection

    JOptionPane.showMessageDialog(null, new JScrollPane(table));

}

The method buildTableModel:

public static DefaultTableModel buildTableModel(ResultSet rs)
        throws SQLException {

    ResultSetMetaData metaData = rs.getMetaData();

    // names of columns
    Vector<String> columnNames = new Vector<String>();
    int columnCount = metaData.getColumnCount();
    for (int column = 1; column <= columnCount; column++) {
        columnNames.add(metaData.getColumnName(column));
    }

    // data of the table
    Vector<Vector<Object>> data = new Vector<Vector<Object>>();
    while (rs.next()) {
        Vector<Object> vector = new Vector<Object>();
        for (int columnIndex = 1; columnIndex <= columnCount; columnIndex++) {
            vector.add(rs.getObject(columnIndex));
        }
        data.add(vector);
    }

    return new DefaultTableModel(data, columnNames);

}

UPDATE

Do you like to use javax.swing.SwingWorker? Do you like to use the try-with-resources statement?

public class GUI extends JFrame {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                new GUI().setVisible(true);
            }
        });
    }

    private final JButton button;
    private final JTable table;
    private final DefaultTableModel tableModel = new DefaultTableModel();

    public GUI() throws HeadlessException {

        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        table = new JTable(tableModel);
        add(new JScrollPane(table), BorderLayout.CENTER);

        button = new JButton("Load Data");
        button.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                new SwingWorker<Void, Void>() {
                    @Override
                    protected Void doInBackground() throws Exception {
                        loadData();
                        return null;
                    }
                }.execute();
            }
        });
        add(button, BorderLayout.PAGE_START);

        setSize(640, 480);
    }

    private void loadData() {
        LOG.info("START loadData method");

        button.setEnabled(false);

        try (Connection conn = DriverManager.getConnection(url, usr, pwd);
                Statement stmt = conn.createStatement()) {

            ResultSet rs = stmt.executeQuery("select * from customer");
            ResultSetMetaData metaData = rs.getMetaData();

            // Names of columns
            Vector<String> columnNames = new Vector<String>();
            int columnCount = metaData.getColumnCount();
            for (int i = 1; i <= columnCount; i++) {
                columnNames.add(metaData.getColumnName(i));
            }

            // Data of the table
            Vector<Vector<Object>> data = new Vector<Vector<Object>>();
            while (rs.next()) {
                Vector<Object> vector = new Vector<Object>();
                for (int i = 1; i <= columnCount; i++) {
                    vector.add(rs.getObject(i));
                }
                data.add(vector);
            }

            tableModel.setDataVector(data, columnNames);
        } catch (Exception e) {
            LOG.log(Level.SEVERE, "Exception in Load Data", e);
        }
        button.setEnabled(true);

        LOG.info("END loadData method");
    }

}

Is there a built-in function to print all the current properties and values of an object?

You are really mixing together two different things.

Use dir(), vars() or the inspect module to get what you are interested in (I use __builtins__ as an example; you can use any object instead).

>>> l = dir(__builtins__)
>>> d = __builtins__.__dict__

Print that dictionary however fancy you like:

>>> print l
['ArithmeticError', 'AssertionError', 'AttributeError',...

or

>>> from pprint import pprint
>>> pprint(l)
['ArithmeticError',
 'AssertionError',
 'AttributeError',
 'BaseException',
 'DeprecationWarning',
...

>>> pprint(d, indent=2)
{ 'ArithmeticError': <type 'exceptions.ArithmeticError'>,
  'AssertionError': <type 'exceptions.AssertionError'>,
  'AttributeError': <type 'exceptions.AttributeError'>,
...
  '_': [ 'ArithmeticError',
         'AssertionError',
         'AttributeError',
         'BaseException',
         'DeprecationWarning',
...

Pretty printing is also available in the interactive debugger as a command:

(Pdb) pp vars()
{'__builtins__': {'ArithmeticError': <type 'exceptions.ArithmeticError'>,
                  'AssertionError': <type 'exceptions.AssertionError'>,
                  'AttributeError': <type 'exceptions.AttributeError'>,
                  'BaseException': <type 'exceptions.BaseException'>,
                  'BufferError': <type 'exceptions.BufferError'>,
                  ...
                  'zip': <built-in function zip>},
 '__file__': 'pass.py',
 '__name__': '__main__'}

Django optional url parameters

There are several approaches.

One is to use a non-capturing group in the regex: (?:/(?P<title>[a-zA-Z]+)/)?
Making a Regex Django URL Token Optional

Another, easier to follow way is to have multiple rules that matches your needs, all pointing to the same view.

urlpatterns = patterns('',
    url(r'^project_config/$', views.foo),
    url(r'^project_config/(?P<product>\w+)/$', views.foo),
    url(r'^project_config/(?P<product>\w+)/(?P<project_id>\w+)/$', views.foo),
)

Keep in mind that in your view you'll also need to set a default for the optional URL parameter, or you'll get an error:

def foo(request, optional_parameter=''):
    # Your code goes here

How to implement the ReLU function in Numpy

There are a couple of ways.

>>> x = np.random.random((3, 2)) - 0.5
>>> x
array([[-0.00590765,  0.18932873],
       [-0.32396051,  0.25586596],
       [ 0.22358098,  0.02217555]])
>>> np.maximum(x, 0)
array([[ 0.        ,  0.18932873],
       [ 0.        ,  0.25586596],
       [ 0.22358098,  0.02217555]])
>>> x * (x > 0)
array([[-0.        ,  0.18932873],
       [-0.        ,  0.25586596],
       [ 0.22358098,  0.02217555]])
>>> (abs(x) + x) / 2
array([[ 0.        ,  0.18932873],
       [ 0.        ,  0.25586596],
       [ 0.22358098,  0.02217555]])

If timing the results with the following code:

import numpy as np

x = np.random.random((5000, 5000)) - 0.5
print("max method:")
%timeit -n10 np.maximum(x, 0)

print("multiplication method:")
%timeit -n10 x * (x > 0)

print("abs method:")
%timeit -n10 (abs(x) + x) / 2

We get:

max method:
10 loops, best of 3: 239 ms per loop
multiplication method:
10 loops, best of 3: 145 ms per loop
abs method:
10 loops, best of 3: 288 ms per loop

So the multiplication seems to be the fastest.

How can I use "e" (Euler's number) and power operation in python 2.7

math.e or from math import e (= 2.718281…)

The two expressions math.exp(x) and e**x are equivalent however:
Return e raised to the power x, where e = 2.718281… is the base of natural logarithms. This is usually more accurate than math.e ** x or pow(math.e, x). docs.python

for power use ** (3**2 = 9), not " ^ "
" ^ " is a bitwise XOR operator (& and, | or), it works logicaly with bits. So for example 10^4=14 (maybe unexpectedly) ? consider the bitwise depiction:

(0000 1010 ^ 0000 0100 = 0000 1110) programiz

How to convert interface{} to string?

You don't need to use a type assertion, instead just use the %v format specifier with Sprintf:

hostAndPort := fmt.Sprintf("%v:%v", arguments["<host>"], arguments["<port>"])

Find commit by hash SHA in Git

There are two ways to do this.

1. providing the SHA of the commit you want to see to git log

git log -p a2c25061

Where -p is short for patch

2. use git show

git show a2c25061

The output for both commands will be:

  • the commit
  • the author
  • the date
  • the commit message
  • the patch information

Non-static method requires a target

Normally it happens when the target is null. So better check the invoke target first then do the linq query.

How to create a Restful web service with input parameters?

You can. Try something like this:

@Path("/todo/{varX}/{varY}")
@Produces({"application/xml", "application/json"})
public Todo whatEverNameYouLike(@PathParam("varX") String varX,
    @PathParam("varY") String varY) {
        Todo todo = new Todo();
        todo.setSummary(varX);
        todo.setDescription(varY);
        return todo;
}

Then call your service with this URL;
http://localhost:8088/JerseyJAXB/rest/todo/summary/description

How to test that no exception is thrown?

Use assertNull(...)

@Test
public void foo() {
    try {
        //execute code that you expect not to throw Exceptions.
    } catch (Exception e){
        assertNull(e);
    }
}

Ordering by specific field value first

One way is this:

select id, name, priority from table a
order by case when name='core' then -1 else priority end asc, priority asc

Understanding lambda in python and using it to pass multiple arguments

Why do you need to state both 'x' and 'y' before the ':'?

Because a lambda is (conceptually) the same as a function, just written inline. Your example is equivalent to

def f(x, y) : return x + y

just without binding it to a name like f.

Also how do you make it return multiple arguments?

The same way like with a function. Preferably, you return a tuple:

lambda x, y: (x+y, x-y)

Or a list, or a class, or whatever.

The thing with self.entry_1.bind should be answered by Demosthenex.

Strange out of memory issue while loading an image to a Bitmap object

I think best way to avoid the OutOfMemoryError is to face it and understand it.

I made an app to intentionally cause OutOfMemoryError, and monitor memory usage.

After I've done a lot of experiments with this App, I've got the following conclusions:

I'm gonna talk about SDK versions before Honey Comb first.

  1. Bitmap is stored in native heap, but it will get garbage collected automatically, calling recycle() is needless.

  2. If {VM heap size} + {allocated native heap memory} >= {VM heap size limit for the device}, and you are trying to create bitmap, OOM will be thrown.

    NOTICE: VM HEAP SIZE is counted rather than VM ALLOCATED MEMORY.

  3. VM Heap size will never shrink after grown, even if the allocated VM memory is shrinked.

  4. So you have to keep the peak VM memory as low as possible to keep VM Heap Size from growing too big to save available memory for Bitmaps.

  5. Manually call System.gc() is meaningless, the system will call it first before trying to grow the heap size.

  6. Native Heap Size will never shrink too, but it's not counted for OOM, so no need to worry about it.

Then, let's talk about SDK Starts from Honey Comb.

  1. Bitmap is stored in VM heap, Native memory is not counted for OOM.

  2. The condition for OOM is much simpler: {VM heap size} >= {VM heap size limit for the device}.

  3. So you have more available memory to create bitmap with the same heap size limit, OOM is less likely to be thrown.

Here is some of my observations about Garbage Collection and Memory Leak.

You can see it yourself in the App. If an Activity executed an AsyncTask that was still running after the Activity was destroyed, the Activity will not get garbage collected until the AsyncTask finish.

This is because AsyncTask is an instance of an anonymous inner class, it holds a reference of the Activity.

Calling AsyncTask.cancel(true) will not stop the execution if the task is blocked in an IO operation in background thread.

Callbacks are anonymous inner classes too, so if a static instance in your project holds them and do not release them, memory would be leaked.

If you scheduled a repeating or delayed task, for example a Timer, and you do not call cancel() and purge() in onPause(), memory would be leaked.

Invoking JavaScript code in an iframe from the parent page

In the IFRAME, make your function public to the window object:

window.myFunction = function(args) {
   doStuff();
}

For access from the parent page, use this:

var iframe = document.getElementById("iframeId");
iframe.contentWindow.myFunction(args);

Node.js Write a line into a .txt file

I did a log file which prints data into text file using "Winston" log. The source code is here below,

const { createLogger, format, transports } = require('winston');
var fs = require('fs')
var logger = fs.createWriteStream('Data Log.txt', {`
flags: 'a' 
})
const os = require('os');
var sleep = require('system-sleep');
var endOfLine = require('os').EOL;
var t = '             ';var s = '         ';var q = '               ';
var array1=[];
var array2=[];
var array3=[];
var array4=[];

array1[0]  =  78;`
array1[1]  =  56;
array1[2]  =  24;
array1[3]  =  34;

for (var n=0;n<4;n++)
{
array2[n]=array1[n].toString();
}

for (var k=0;k<4;k++)
{
array3[k]=Buffer.from('                    ');
}

for (var a=0;a<4;a++)  
{
array4[a]=Buffer.from(array2[a]);
}

for (m=0;m<4;m++)
{
array4[m].copy(array3[m],0);
}

logger.write('Date'+q);
logger.write('Time'+(q+'  '))
logger.write('Data 01'+t);
logger.write('Data 02'+t); 
logger.write('Data 03'+t);
logger.write('Data 04'+t)

logger.write(endOfLine);
logger.write(endOfLine);
enter code here`enter code here`
}

function mydata()      //user defined function
{
logger.write(datechar+s);
logger.write(timechar+s);
for ( n = 0; n < 4; n++) 
{
logger.write(array3[n]);
}
logger.write(endOfLine); 
}

for (;;)
}
var now = new Date();
var dateFormat = require('dateformat');
var date = dateFormat(now,"isoDate");
var time = dateFormat(now, "h:MM:ss TT ");
var datechar = date.toString();
var timechar = time.toString();
mydata();
sleep(5*1000);
}

AngularJS sorting rows by table header

Try this:

First change your controller

    yourModuleName.controller("yourControllerName", function ($scope) {
        var list = [
            { H1:'A', H2:'B', H3:'C', H4:'d' },
            { H1:'E', H2:'B', H3:'F', H4:'G' },
            { H1:'C', H2:'H', H3:'L', H4:'M' },
            { H1:'I', H2:'B', H3:'E', H4:'A' }
        ];

        $scope.list = list;

        $scope.headers = ["Header1", "Header2", "Header3", "Header4"];

        $scope.sortColumn = 'Header1';

        $scope.reverseSort = false;

        $scope.sortData = function (columnIndex) {
            $scope.reverseSort = ($scope.sortColumn == $scope.headers[columnIndex]) ? !$scope.reverseSort : false;

            $scope.sortColumn = $scope.headers[columnIndex];
        }

    });

then change code in html side like this

    <th ng-repeat= "header in headers">
            <a ng-click="sortData($index)"> {{headers[$index]}} </a>
    </th>
    <tr ng-repeat "result in results | orderBy : sortColumn : reverseSort">
        <td> {{results.h1}} </td>
        <td> {{results.h2}} </td>
        <td> {{results.h3}} </td>
        <td> {{results.h4}} </td>
    </tr>

Windows batch: echo without new line

Using set and the /p parameter you can echo without newline:

C:\> echo Hello World
Hello World

C:\> echo|set /p="Hello World"
Hello World
C:\>

Source

How to get the number of columns in a matrix?

When want to get row size with size() function, below code can be used:

size(A,1)

Another usage for it:

[height, width] = size(A)

So, you can get 2 dimension of your matrix.

Difference between matches() and find() in Java Regex

matches(); does not buffer, but find() buffers. find() searches to the end of the string first, indexes the result, and return the boolean value and corresponding index.

That is why when you have a code like

1:Pattern.compile("[a-z]");

2:Pattern.matcher("0a1b1c3d4");

3:int count = 0;

4:while(matcher.find()){

5:count++: }

At 4: The regex engine using the pattern structure will read through the whole of your code (index to index as specified by the regex[single character] to find at least one match. If such match is found, it will be indexed then the loop will execute based on the indexed result else if it didn't do ahead calculation like which matches(); does not. The while statement would never execute since the first character of the matched string is not an alphabet.

scp from Linux to Windows

As @Hesham Eraqi suggested, it worked for me in this way (transfering from Ubuntu to Windows (I tried to add a comment in that answer but because of reputation, I couldn't)):

pscp -v -r -P 53670 [email protected]:/data/genetic_map/sample/P2_283/* \\Desktop-mojbd3n\d\cc_01-1940_data\

where:

-v: show verbose messages.
-r: copy directories recursively.
-P: connect to specified port.
53670: the port number to connect the Ubuntu server.
\\Desktop-mojbd3n\d\genetic_map_data\: I needed to transfer to an external HDD, thus I had to give permissions of sharing to this device.

How to display string that contains HTML in twig template?

if you don't need variable, you can define text in
translations/messages.en.yaml :
CiteExampleHtmlCode: "<b> my static text </b>"

then use it with twig:
templates/about/index.html.twig
… {{ 'CiteExampleHtmlCode' }}
or if you need multilangages like me:
… {{ 'CiteExampleHtmlCode' | trans }}

Let's have a look of https://symfony.com/doc/current/translation.html for more information about translations use.

Random integer in VB.NET

To get a random integer value between 1 and N (inclusive) you can use the following.

CInt(Math.Ceiling(Rnd() * n)) + 1

Usage of __slots__?

Each python object has a __dict__ atttribute which is a dictionary containing all other attributes. e.g. when you type self.attr python is actually doing self.__dict__['attr']. As you can imagine using a dictionary to store attribute takes some extra space & time for accessing it.

However, when you use __slots__, any object created for that class won't have a __dict__ attribute. Instead, all attribute access is done directly via pointers.

So if want a C style structure rather than a full fledged class you can use __slots__ for compacting size of the objects & reducing attribute access time. A good example is a Point class containing attributes x & y. If you are going to have a lot of points, you can try using __slots__ in order to conserve some memory.

How to dynamically load a Python class

def import_class(cl):
    d = cl.rfind(".")
    classname = cl[d+1:len(cl)]
    m = __import__(cl[0:d], globals(), locals(), [classname])
    return getattr(m, classname)

npm WARN package.json: No repository field

It's just a check as of NPM v1.2.20, they report this as a warning.

However, don't worry, there are sooooooo many packages which still don't have the repository field in their package.json. The field is used for informational purposes.

In the case you're a package author, put the repository in your package.json, like this:

"repository": {
  "type": "git",
  "url": "git://github.com/username/repository.git"
}

Read more about the repository field, and see the logged bug for further details.


Additionally, as originally reported by @dan_nl, you can set private key in your package.json.
This will not only stop you from accidentally running npm publish in your app, but will also stop NPM from printing warnings regarding package.json problems.

{
  "name": "my-super-amazing-app",
  "version": "1.0.0",
  "private": true
}

How to check if a stored procedure exists before creating it

As of SQL SERVER 2016 you can use the new DROP PROCEDURE IF EXISTS.
DROP { PROC | PROCEDURE } [ IF EXISTS ] { [ schema_name. ] procedure } [ ,...n ]

Reference : https://msdn.microsoft.com/en-us/library/ms174969.aspx

How can I retrieve a table from stored procedure to a datatable?

string connString = "<your connection string>";
string sql = "name of your sp";

using(SqlConnection conn = new SqlConnection(connString)) 
{
    try 
    {
        using(SqlDataAdapter da = new SqlDataAdapter()) 
        {
            da.SelectCommand = new SqlCommand(sql, conn);
            da.SelectCommand.CommandType = CommandType.StoredProcedure;

            DataSet ds = new DataSet();   
            da.Fill(ds, "result_name");

            DataTable dt = ds.Tables["result_name"];

            foreach (DataRow row in dt.Rows) {
                //manipulate your data
            }
        }    
    } 
    catch(SQLException ex) 
    {
        Console.WriteLine("SQL Error: " + ex.Message);
    }
    catch(Exception e) 
    {
        Console.WriteLine("Error: " + e.Message);
    }
}

Modified from Java Schools Example

Load properties file in JAR?

For the record, this is documented in How do I add resources to my JAR? (illustrated for unit tests but the same applies for a "regular" resource):

To add resources to the classpath for your unit tests, you follow the same pattern as you do for adding resources to the JAR except the directory you place resources in is ${basedir}/src/test/resources. At this point you would have a project directory structure that would look like the following:

my-app
|-- pom.xml
`-- src
    |-- main
    |   |-- java
    |   |   `-- com
    |   |       `-- mycompany
    |   |           `-- app
    |   |               `-- App.java
    |   `-- resources
    |       `-- META-INF
    |           |-- application.properties
    `-- test
        |-- java
        |   `-- com
        |       `-- mycompany
        |           `-- app
        |               `-- AppTest.java
        `-- resources
            `-- test.properties

In a unit test you could use a simple snippet of code like the following to access the resource required for testing:

...

// Retrieve resource
InputStream is = getClass().getResourceAsStream("/test.properties" );

// Do something with the resource

...

Can Powershell Run Commands in Parallel?

Backgrounds jobs are expensive to setup and are not reusable. PowerShell MVP Oisin Grehan has a good example of PowerShell multi-threading.

(10/25/2010 site is down, but accessible via the Web Archive).

I'e used adapted Oisin script for use in a data loading routine here:

http://rsdd.codeplex.com/SourceControl/changeset/view/a6cd657ea2be#Invoke-RSDDThreaded.ps1

How to change the URI (URL) for a remote Git repository?

  1. remove origin using command on gitbash git remote rm origin
  2. And now add new Origin using gitbash git remote add origin (Copy HTTP URL from your project repository in bit bucket) done

Remove all occurrences of a value from a list?

I believe this is probably faster than any other way if you don't care about the lists order, if you do take care about the final order store the indexes from the original and resort by that.

category_ids.sort()
ones_last_index = category_ids.count('1')
del category_ids[0:ones_last_index]

MAX(DATE) - SQL ORACLE

SELECT p.MEMBSHIP_ID
FROM user_payments as p
WHERE USER_ID = 1 AND PAYM_DATE = (
    SELECT MAX(p2.PAYM_DATE)
    FROM user_payments as p2
    WHERE p2.USER_ID = p.USER_ID
)

What does the ELIFECYCLE Node.js error mean?

When running Webpack build I was getting similar error because node doesn't understand async await keywords on older versions. I added webpack babel-plugin-transform-async-to-generator and it was solved. This replaces them with promises.

Splitting words into letters in Java

String[] result = "Stack Me 123 Heppa1 oeu".split("**(?<=\\G.{1})**");
System.out.println(java.util.Arrays.toString(result));

How to print all information from an HTTP request to the screen, in PHP

Nobody mentioned how to dump HTTP headers correctly under any circumstances.

From CGI specification rfc3875, section 4.1.18:

Meta-variables with names beginning with "HTTP_" contain values read from the client request header fields, if the protocol used is HTTP. The HTTP header field name is converted to upper case, has all occurrences of "-" replaced with "" and has "HTTP" prepended to give the meta-variable name.

foreach ($_SERVER as $key => $value) {
    if (strpos($key, 'HTTP_') === 0) {
        $chunks = explode('_', $key);
        $header = '';
        for ($i = 1; $y = sizeof($chunks) - 1, $i < $y; $i++) {
            $header .= ucfirst(strtolower($chunks[$i])).'-';
        }
        $header .= ucfirst(strtolower($chunks[$i])).': '.$value;
        echo $header.'<br>';
    }
}

Details: http://cmyker.blogspot.com/2012/10/how-to-dump-http-headers-with-php.html

Node.js + Nginx - What now?

Node.js with Nginx configuration.

$ sudo nano /etc/nginx/sites-available/subdomain.your_domain.com

add the following configuration so that Nginx acting as a proxy redirect to port 3000 traffic from the server when we come from “subdomain.your_domain.com”

upstream subdomain.your_domain.com {
  server 127.0.0.1:3000;
}
server {
  listen 80;
  listen [::]:80;
  server_name subdomain.your_domain.com;
  access_log /var/log/nginx/subdomain.your_domain.access.log;
  error_log /var/log/nginx/subdomain.your_domain.error.log debug;
  location / {
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarder-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_set_header X-NginX-Proxy true;
    proxy_pass http://subdomain.your_domain.com;
    proxy_redirect off;
  }
}

Why is vertical-align:text-top; not working in CSS

something like

  position:relative;
  top:-5px;

just on the inline element itself works for me. Have to play with the top to get it centered vertically...

ASP.NET GridView RowIndex As CommandArgument

with paging you need to do some calculation

int index = Convert.ToInt32(e.CommandArgument) % GridView1.PageSize;

SQLite in Android How to update a specific row

For updates, need to call setTransactionSuccessfull for changes to get committed like so:

db.beginTransaction();
try {
    db.update(...) 
    db.setTransactionSuccessfull(); // changes get rolled back if this not called
} finally {
   db.endTransaction(); // commit or rollback
}

Trying to load local JSON file to show data in a html page using JQuery

I have Used Following Methods But non of them worked:

   // 2 Method Failed

        $.get(
            'http://www.corsproxy.com/' +
            'en.github.com/FEND16/movie-json-data/blob/master/json/movies-coming-soon.json',
            function (response) {
                console.log("> ", response);
                $("#viewer").html(response);
            });
// 3 Method Failed

    var jqxhr = $.getJSON( "./json/movies-coming-soon.json", function() {
  console.log( "success" );
})
  .done(function() {
    console.log( "second success" );
  })
  .fail(function() {
    console.log( "error" );
  })
  .always(function() {
    console.log( "complete" );
  });

// Perform other work here ...

// Set another completion function for the request above
jqxhr.always(function() {
  console.log( "second complete" );
});

// 4 Method Failed

$.ajax({
   type: 'POST',
   crossDomain: true,
   dataType: 'jsonp',
   url: 'https://github.com/FEND16/movie-json-data/blob/master/json/movies-coming-soon.json',
   success: function(jsondata){
    console.log(jsondata)
   }
})

// 5 Method Failed


$.ajax({
   url: 'https://github.com/FEND16/movie-json-data/blob/master/json/movies-coming-soon.json',
   headers: {  'Access-Control-Allow-Origin': 'htt://site allowed to access' },
   dataType: 'jsonp',
   /* etc */
   success: function(jsondata){

   }
})

What worked For me to simply download chrome extension called "200 OK!" or Web server for chrome and write my code like this:

// Worked After local Web Server

        $(document).ready(function () {
            $.getJSON('./json/movies-coming-soon.json', function (data) {
              var movie_name = '';
              var movie_year = '';
                $.each(data,function(i,item){
                    console.log(item.title,item.year,item.poster)
                    movie_name += item.title + "  " + item.year + "<br> <br>"

                    $('#movie_name').html(movie_name)


                })

            })

        })

Its because you can not access local file without running local web server as per CORS policy so in order to running it you must have some host server.

Display only 10 characters of a long string?

Although this won't limit the string to exactly 10 characters, why not let the browser do the work for you with CSS:

.no-overflow {
    white-space: no-wrap;
    text-overflow: ellipsis;
    overflow: hidden;
}

and then for the table cell that contains the string add the above class and set the maximum permitted width. The result should end up looking better than anything done based on measuring the string length.

Pandas: Looking up the list of sheets in an excel file

You should explicitly specify the second parameter (sheetname) as None. like this:

 df = pandas.read_excel("/yourPath/FileName.xlsx", None);

"df" are all sheets as a dictionary of DataFrames, you can verify it by run this:

df.keys()

result like this:

[u'201610', u'201601', u'201701', u'201702', u'201703', u'201704', u'201705', u'201706', u'201612', u'fund', u'201603', u'201602', u'201605', u'201607', u'201606', u'201608', u'201512', u'201611', u'201604']

please refer pandas doc for more details: https://pandas.pydata.org/pandas-docs/stable/generated/pandas.read_excel.html

javascript: detect scroll end

if ((window.innerHeight + window.scrollY) >= document.body.offsetHeight)
{
//your code here
}

I too searched it and even after checking all comments here and more, this is the solution to check if reached the bottom or not.

Video streaming over websockets using JavaScript

To answer the question:

What is the fastest way to stream live video using JavaScript? Is WebSockets over TCP a fast enough protocol to stream a video of, say, 30fps?

Yes, Websocket can be used to transmit over 30 fps and even 60 fps.

The main issue with Websocket is that it is low-level and you have to deal with may other issues than just transmitting video chunks. All in all it's a great transport for video and also audio.

How can I convert a string to upper- or lower-case with XSLT?

.NET XSLT implementation allows to write custom managed functions in the stylesheet. For lower-case() it can be:

<?xml version="1.0" encoding="utf-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:msxsl="urn:schemas-microsoft-com:xslt" xmlns:utils="urn:myExtension" exclude-result-prefixes="msxsl">

  <xsl:output method="xml" indent="yes"/>

  <msxsl:script implements-prefix="utils" language="C#">
    <![CDATA[
      public string ToLower(string stringValue)
      {
        string result = String.Empty;

        if(!String.IsNullOrEmpty(stringValue))
        {
          result = stringValue.ToLower(); 
        }

        return result;
      }
    ]]>
  </msxsl:script>

  <!-- using of our custom function -->
  <lowercaseValue>
    <xsl:value-of select="utils:ToLower($myParam)"/>
  </lowercaseValue>

Assume, that can be slow, but still acceptable.

Do not forget to enable embedded scripts support for transform:

// Create the XsltSettings object with script enabled.
XsltSettings xsltSettings = new XsltSettings(false, true);

XslCompiledTransform xslt = new XslCompiledTransform();

// Load stylesheet
xslt.Load(xsltPath, xsltSettings, new XmlUrlResolver());

Accessing JSON elements

Just for more one option...You can do it this way too:

MYJSON = {
    'username': 'gula_gut',
    'pics': '/0/myfavourite.jpeg',
    'id': '1'
}

#changing username
MYJSON['username'] = 'calixto'
print(MYJSON['username'])

I hope this can help.

Unable to login to SQL Server + SQL Server Authentication + Error: 18456

By default login failed error message is nothing but a client user connection has been refused by the server due to mismatch of login credentials. First task you might check is to see whether that user has relevant privileges on that SQL Server instance and relevant database too, thats good. Obviously if the necessary prvileges are not been set then you need to fix that issue by granting relevant privileges for that user login.

Althought if that user has relevant grants on database & server if the Server encounters any credential issues for that login then it will prevent in granting the authentication back to SQL Server, the client will get the following error message:

Msg 18456, Level 14, State 1, Server <ServerName>, Line 1
Login failed for user '<Name>'

Ok now what, by looking at the error message you feel like this is non-descriptive to understand the Level & state. By default the Operating System error will show 'State' as 1 regardless of nature of the issues in authenticating the login. So to investigate further you need to look at relevant SQL Server instance error log too for more information on Severity & state of this error. You might look into a corresponding entry in log as:

2007-05-17 00:12:00.34 Logon     Error: 18456, Severity: 14, State: 8.
or

2007-05-17 00:12:00.34 Logon     Login failed for user '<user name>'.

As defined above the Severity & State columns on the error are key to find the accurate reflection for the source of the problem. On the above error number 8 for state indicates authentication failure due to password mismatch. Books online refers: By default, user-defined messages of severity lower than 19 are not sent to the Microsoft Windows application log when they occur. User-defined messages of severity lower than 19 therefore do not trigger SQL Server Agent alerts.

Sung Lee, Program Manager in SQL Server Protocols (Dev.team) has outlined further information on Error state description:The common error states and their descriptions are provided in the following table:

ERROR STATE       ERROR DESCRIPTION
------------------------------------------------------------------------------
2 and 5           Invalid userid
6                 Attempt to use a Windows login name with SQL Authentication
7                 Login disabled and password mismatch
8                 Password mismatch
9                 Invalid password
11 and 12         Valid login but server access failure
13                SQL Server service paused
18                Change password required


Well I'm not finished yet, what would you do in case of error:

2007-05-17 00:12:00.34 Logon     Login failed for user '<user name>'.

You can see there is no severity or state level defined from that SQL Server instance's error log. So the next troubleshooting option is to look at the Event Viewer's security log [edit because screen shot is missing but you get the

idea, look in the event log for interesting events].

Dealing with nginx 400 "The plain HTTP request was sent to HTTPS port" error

I had the exact same issue, I have kind of the same configuration as your exemple and I got it working by removing the line :

ssl on;

To quote the doc:

If HTTP and HTTPS servers are equal, a single server that handles both HTTP and HTTPS requests may be configured by deleting the directive “ssl on” and adding the ssl parameter for *:443 port

How to turn on line numbers in IDLE?

As @StahlRat already answered. I would like to add another method for it. There is extension pack for Python Default idle editor Python Extensions Package.

Re-doing a reverted merge in Git

Let's assume you have such history

---o---o---o---M---W---x-------x-------*
              /                      
      ---A---B

Where A, B failed commits and W - is revert of M

So before I start fixing found problems I do cherry-pick of W commit to my branch

git cherry-pick -x W

Then I revert W commit on my branch

git revert W 

After I can continue fixing.

The final history could look like:

---o---o---o---M---W---x-------x-------*
              /                       /     
      ---A---B---W---W`----------C---D

When I send a PR it will clearly shows that PR is undo revert and adds some new commits.

What is the difference between single and double quotes in SQL?

Single quotes delimit a string constant or a date/time constant.

Double quotes delimit identifiers for e.g. table names or column names. This is generally only necessary when your identifier doesn't fit the rules for simple identifiers.

See also:

You can make MySQL use double-quotes per the ANSI standard:

SET GLOBAL SQL_MODE=ANSI_QUOTES

You can make Microsoft SQL Server use double-quotes per the ANSI standard:

SET QUOTED_IDENTIFIER ON

Vue equivalent of setTimeout?

Arrow Function

The best and simplest way to solve this problem is by using an arrow function () => {}:

    addToBasket() {
        var item = this.photo;
        this.$http.post('/api/buy/addToBasket', item);
        this.basketAddSuccess = true;
        // now 'this' is referencing the Vue object and not the 'setTimeout' scope
        setTimeout(() => this.basketAddSuccess = false, 2000);
    }

This works because the this of arrow functions is bound to the this of its enclosing scope- in Vue, that's the parent/ enclosing component. Inside a traditional function called by setTimeout, however, this refers to the window object (which is why you ran into errors when you tried to access this.basketAddSuccess in that context).

Argument Passing

Another way of doing this would be passing this as an arg to your function through setTimeout's prototype using its setTimeout(callback, delay, arg1, arg2, ...) form:

    addToBasket() {
        item = this.photo;
        this.$http.post('/api/buy/addToBasket', item);
        this.basketAddSuccess = true;
        //Add scope argument to func, pass this after delay in setTimeout
        setTimeout(function(scope) {
             scope.basketAddSuccess = false;
        }, 2000, this);
    }

(It's worth noting that the arg passing syntax is incompatible with IE 9 and below, however.)

Create a pointer to two-dimensional array

You can do it like this:

uint8_t (*matrix_ptr)[10][20] = &l_matrix;

Get element by id - Angular2

(<HTMLInputElement>document.getElementById('loginInput')).value = '123';

Angular cannot take HTML elements directly thereby you need to specify the element type by binding the above generic to it.

UPDATE::

This can also be done using ViewChild with #localvariable as shown here, as mentioned in here

<textarea  #someVar  id="tasknote"
                  name="tasknote"
                  [(ngModel)]="taskNote"
                  placeholder="{{ notePlaceholder }}"
                  style="background-color: pink"
                  (blur)="updateNote() ; noteEditMode = false " (click)="noteEditMode = false"> {{ todo.note }} 

</textarea>

import {ElementRef,Renderer2} from '@angular/core';
@ViewChild('someVar') el:ElementRef;

constructor(private rd: Renderer2) {}

ngAfterViewInit() {
      console.log(this.rd); 
      this.el.nativeElement.focus();      //<<<=====same as oldest way
}

What is String pool in Java?

This prints true (even though we don't use equals method: correct way to compare strings)

    String s = "a" + "bc";
    String t = "ab" + "c";
    System.out.println(s == t);

When compiler optimizes your string literals, it sees that both s and t have same value and thus you need only one string object. It's safe because String is immutable in Java.
As result, both s and t point to the same object and some little memory saved.

Name 'string pool' comes from the idea that all already defined string are stored in some 'pool' and before creating new String object compiler checks if such string is already defined.

How do I change the default application icon in Java?

inside frame constructor

try{    
       setIconImage(ImageIO.read(new File("./images/icon.png")));   
   }
catch (Exception ex){
       //do something
   }

javascript popup alert on link click

just make it function,

<script type="text/javascript">
function AlertIt() {
var answer = confirm ("Please click on OK to continue.")
if (answer)
window.location="http://www.continue.com";
}
</script>

<a href="javascript:AlertIt();">click me</a>

Retrieve CPU usage and memory usage of a single process on Linux?

Launch a program and monitor it

This form is useful if you want to benchmark an executable easily:

topp() (
  $* &>/dev/null &
  pid="$!"
  trap ':' INT
  echo 'CPU  MEM'
  while sleep 1; do ps --no-headers -o '%cpu,%mem' -p "$pid"; done
  kill "$pid"
)
topp ./myprog arg1 arg2

Now when you hit Ctrl + C it exits the program and stops monitoring. Sample output:

CPU  MEM
20.0  1.3
35.0  1.3
40.0  1.3

Related: https://unix.stackexchange.com/questions/554/how-to-monitor-cpu-memory-usage-of-a-single-process

Tested on Ubuntu 16.04.

How to change Apache Tomcat web server port number

You need to edit the Tomcat/conf/server.xml and change the connector port. The connector setting should look something like this:

<Connector port="8080" maxHttpHeaderSize="8192"
           maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
           enableLookups="false" redirectPort="8443" acceptCount="100"
           connectionTimeout="20000" disableUploadTimeout="true" />

Just change the connector port from default 8080 to another valid port number.

Java collections maintaining insertion order

Theres's a section in the O'Reilly Java Cookbook called "Avoiding the urge to sort" The question you should be asking is actually the opposite of your original question ... "Do we gain something by sorting?" It take a lot of effort to sort and maintain that order. Sure sorting is easy but it usually doesn't scale in most programs. If you're going to be handling thousands or tens of thousands of requests (insrt,del,get,etc) per second whether not you're using a sorted or non sorted data structure is seriously going to matter.

ng-repeat: access key and value for each object in array of objects

In case this is an option for you, if you put your data into object form it works the way I think you're hoping for:

$scope.steps = {
 companyName: true,
 businessType: true,
 physicalAddress: true
};

Here's a fiddle of this: http://jsfiddle.net/zMjVp/

How to change the default background color white to something else in twitter bootstrap

Its not recommended to overwrite bootstrap file, just in your local style.css use

body{background: your color !important;

here !important declaration overwrite bootstrap value.

getting a checkbox array value from POST

Check out the implode() function as an alternative. This will convert the array into a list. The first param is how you want the items separated. Here I have used a comma with a space after it.

$invite = implode(', ', $_POST['invite']);
echo $invite;

How to remove all namespaces from XML with C#?

I tried some of the solutions, but as stated by so many, there are some edge cases.

Used some of the regexes above, but came to the conclusion that a one step regex is not feasable.

So here is my solution, 2 step regex, find tags, within tags remove, do not alter cdata:

            Func<Match, String> NamespaceRemover = delegate (Match match)
            {
                var result = match.Value;
                if (String.IsNullOrEmpty(match.Groups["cdata"].Value))
                {
                    // find all prefixes within start-, end tag and attributes and also namespace declarations
                    return Regex.Replace(result, "((?<=<|<\\/| ))\\w+:| xmlns(:\\w+)?=\".*?\"", "");
                }
                else
                {
                    // cdata as is
                    return result;
                }
            };
            // XmlDocument doc;
            // string file;
            doc.LoadXml(
              Regex.Replace(File.ReadAllText(file), 
                // find all begin, cdata and end tags (do not change order)
                @"<(?:\w+:?\w+.*?|(?<cdata>!\[CDATA\[.*?\]\])|\/\w+:?\w+)>", 
                new MatchEvaluator(NamespaceRemover)
              )
            );

For now it is 100% working for me.

How do I add an "Add to Favorites" button or link on my website?

Credit to @Gert Grenander , @Alaa.Kh , and Ross Shanon

Trying to make some order:

it all works - all but the firefox bookmarking function. for some reason the 'window.sidebar.addPanel' is not a function for the debugger, though it is working fine.

The problem is that it takes its values from the calling <a ..> tag: title as the bookmark name and href as the bookmark address. so this is my code:

javascript:

$("#bookmarkme").click(function () {
  var url = 'http://' + location.host; // i'm in a sub-page and bookmarking the home page
  var name = "Snir's Homepage";

  if (navigator.userAgent.toLowerCase().indexOf('chrome') > -1){ //chrome
    alert("In order to bookmark go to the homepage and press " 
        + (navigator.userAgent.toLowerCase().indexOf('mac') != -1 ? 
            'Command/Cmd' : 'CTRL') + "+D.")
  } 
  else if (window.sidebar) { // Mozilla Firefox Bookmark
    //important for firefox to add bookmarks - remember to check out the checkbox on the popup
    $(this).attr('rel', 'sidebar');
    //set the appropriate attributes
    $(this).attr('href', url);
    $(this).attr('title', name);

    //add bookmark:
    //  window.sidebar.addPanel(name, url, '');
    //  window.sidebar.addPanel(url, name, '');
    window.sidebar.addPanel('', '', '');
  } 
  else if (window.external) { // IE Favorite
        window.external.addFavorite(url, name);
  } 
  return;
});

html:

  <a id="bookmarkme" href="#" title="bookmark this page">Bookmark This Page</a>

In internet explorer there is a different between 'addFavorite': <a href="javascript:window.external.addFavorite('http://tiny.cc/snir','snir-site')">..</a> and 'AddFavorite': <span onclick="window.external.AddFavorite(location.href, document.title);">..</span>.

example here: http://www.yourhtmlsource.com/javascript/addtofavorites.html

Important, in chrome we can't add bookmarks using js (aspnet-i): http://www.codeproject.com/Questions/452899/How-to-add-bookmark-in-Google-Chrome-Opera-and-Saf

Window.Open with PDF stream instead of PDF location

Note: I have verified this in the latest version of IE, and other browsers like Mozilla and Chrome and this works for me. Hope it works for others as well.

if (data == "" || data == undefined) {
    alert("Falied to open PDF.");
} else { //For IE using atob convert base64 encoded data to byte array
    if (window.navigator && window.navigator.msSaveOrOpenBlob) {
        var byteCharacters = atob(data);
        var byteNumbers = new Array(byteCharacters.length);
        for (var i = 0; i < byteCharacters.length; i++) {
            byteNumbers[i] = byteCharacters.charCodeAt(i);
        }
        var byteArray = new Uint8Array(byteNumbers);
        var blob = new Blob([byteArray], {
            type: 'application/pdf'
        });
        window.navigator.msSaveOrOpenBlob(blob, fileName);
    } else { // Directly use base 64 encoded data for rest browsers (not IE)
        var base64EncodedPDF = data;
        var dataURI = "data:application/pdf;base64," + base64EncodedPDF;
        window.open(dataURI, '_blank');
    }

}

How to change default install location for pip

You can set the following environment variable:

PIP_TARGET=/path/to/pip/dir

https://pip.pypa.io/en/stable/user_guide/#environment-variables

Postgres manually alter sequence

I don't try changing sequence via setval. But using ALTER I was issued how to write sequence name properly. And this only work for me:

  1. Check required sequence name using SELECT * FROM information_schema.sequences;

  2. ALTER SEQUENCE public."table_name_Id_seq" restart {number};

    In my case it was ALTER SEQUENCE public."Services_Id_seq" restart 8;

Also there is a page on wiki.postgresql.org where describes a way to generate sql script to fix sequences in all database tables at once. Below the text from link:

Save this to a file, say 'reset.sql'

SELECT 'SELECT SETVAL(' ||
       quote_literal(quote_ident(PGT.schemaname) || '.' || quote_ident(S.relname)) ||
       ', COALESCE(MAX(' ||quote_ident(C.attname)|| '), 1) ) FROM ' ||
       quote_ident(PGT.schemaname)|| '.'||quote_ident(T.relname)|| ';'
FROM pg_class AS S,
     pg_depend AS D,
     pg_class AS T,
     pg_attribute AS C,
     pg_tables AS PGT
WHERE S.relkind = 'S'
    AND S.oid = D.objid
    AND D.refobjid = T.oid
    AND D.refobjid = C.attrelid
    AND D.refobjsubid = C.attnum
    AND T.relname = PGT.tablename
ORDER BY S.relname;

Run the file and save its output in a way that doesn't include the usual headers, then run that output. Example:

psql -Atq -f reset.sql -o temp
psql -f temp
rm temp

And the output will be a set of sql commands which look exactly like this:

SELECT SETVAL('public."SocialMentionEvents_Id_seq"', COALESCE(MAX("Id"), 1) ) FROM public."SocialMentionEvents";
SELECT SETVAL('public."Users_Id_seq"', COALESCE(MAX("Id"), 1) ) FROM public."Users";

Writing outputs to log file and console

I have found a way to get the desired output. Though it may be somewhat unorthodox way. Anyways here it goes. In the redir.env file I have following code:

#####redir.env#####    
export LOG_FILE=log.txt

      exec 2>>${LOG_FILE}

    function log {
     echo "$1">>${LOG_FILE}
    }

    function message {
     echo "$1"
     echo "$1">>${LOG_FILE}
    }

Then in the actual script I have the following codes:

#!/bin/sh 
. redir.env
echo "Echoed to console only"
log "Written to log file only"
message "To console and log"
echo "This is stderr. Written to log file only" 1>&2

Here echo outputs only to console, log outputs to only log file and message outputs to both the log file and console.

After executing the above script file I have following outputs:

In console

In console
Echoed to console only
To console and log

For the Log file

In Log File Written to log file only
This is stderr. Written to log file only
To console and log

Hope this help.

Which is fastest? SELECT SQL_CALC_FOUND_ROWS FROM `table`, or SELECT COUNT(*)

Removing some unnecessary SQL and then COUNT(*) will be faster than SQL_CALC_FOUND_ROWS. Example:

SELECT Person.Id, Person.Name, Job.Description, Card.Number
FROM Person
JOIN Job ON Job.Id = Person.Job_Id
LEFT JOIN Card ON Card.Person_Id = Person.Id
WHERE Job.Name = 'WEB Developer'
ORDER BY Person.Name

Then count without unnecessary part:

SELECT COUNT(*)
FROM Person
JOIN Job ON Job.Id = Person.Job_Id
WHERE Job.Name = 'WEB Developer'

Convert HTML to PDF in .NET

Essential PDF can be used to convert HTML to PDF: C# sample. The sample linked to here is ASP.NET based, but the library can be used from Windows Forms, WPF, ASP.NET Webforms, and ASP.NET MVC. The library offers the option of using different HTML rendering engines : Internet Explorer (default) and WebKit (best output).

The whole suite of controls is available for free (commercial applications also) through the community license program if you qualify. The community license is the full product with no limitations or watermarks.

Note: I work for Syncfusion.

twitter bootstrap autocomplete dropdown / combobox with Knockoutjs

Can i suggest http://www.jqueryscript.net/form/Twitter-Like-Mentions-Auto-Suggesting-Plugin-with-jQuery-Bootstrap-Suggest.html, works more like the twitter post suggestion where it gives you a list of users or topics based on @ or # tags,

view demo here: http://www.jqueryscript.net/demo/Twitter-Like-Mentions-Auto-Suggesting-Plugin-with-jQuery-Bootstrap-Suggest/

in this one you can easily change the @ and # to anything you want

C#: HttpClient with POST parameters

As Ben said, you are POSTing your request ( HttpMethod.Post specified in your code )

The querystring (get) parameters included in your url probably will not do anything.

Try this:

string url = "http://myserver/method";    
string content = "param1=1&param2=2";
HttpClientHandler handler = new HttpClientHandler();
HttpClient httpClient = new HttpClient(handler);
HttpRequestMessage request = new HttpRequestMessage(HttpMethod.Post, url);
HttpResponseMessage response = await httpClient.SendAsync(request,content);

HTH,

bovako

VideoView Full screen in android application

First Method

when you want to open a video in full screen for that Activity you have to set the theme attribute in the Manifest. set this value that is

android:theme="@android:style/Theme.NoTitleBar.Fullscreen"

change theme programmatically here

Second Method

create another fullscreen.xml like below and setContentView(R.layout.fullscreen) on click of the button

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <VideoView android:id="@+id/myvideoview"
        android:layout_width="fill_parent"
        android:layout_alignParentRight="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_alignParentBottom="true"
        android:layout_height="fill_parent">
    </VideoView>

</RelativeLayout>

Can we have multiple "WITH AS" in single sql - Oracle SQL

Yes you can...

WITH SET1 AS (SELECT SYSDATE FROM DUAL), -- SET1 initialised
     SET2 AS (SELECT * FROM SET1)        -- SET1 accessed
SELECT * FROM SET2;                      -- SET2 projected

10/29/2013 10:43:26 AM

Follow the order in which it should be initialized in Common Table Expressions

correct way to use super (argument passing)

As explained in Python's super() considered super, one way is to have class eat the arguments it requires, and pass the rest on. Thus, when the call-chain reaches object, all arguments have been eaten, and object.__init__ will be called without arguments (as it expects). So your code should look like this:

class A(object):
    def __init__(self, *args, **kwargs):
        print "A"
        super(A, self).__init__(*args, **kwargs)

class B(object):
    def __init__(self, *args, **kwargs):
        print "B"
        super(B, self).__init__(*args, **kwargs)

class C(A):
    def __init__(self, arg, *args, **kwargs):
        print "C","arg=",arg
        super(C, self).__init__(*args, **kwargs)

class D(B):
    def __init__(self, arg, *args, **kwargs):
        print "D", "arg=",arg
        super(D, self).__init__(*args, **kwargs)

class E(C,D):
    def __init__(self, arg, *args, **kwargs):
        print "E", "arg=",arg
        super(E, self).__init__(*args, **kwargs)

print "MRO:", [x.__name__ for x in E.__mro__]
E(10, 20, 30)

Connecting to Oracle Database through C#?

The next approach work to me with Visual Studio 2013 Update 4 1- From Solution Explorer right click on References then select add references 2- Assemblies > Framework > System.Data.OracleClient > OK and after that you free to add using System.Data.OracleClient in your application and deal with database like you do with Sql Server database except changing the prefix from Sql to Oracle as in SqlCommand become OracleCommand for example to link to Oracle XE

OracleConnection oraConnection = new OracleConnection(@"Data Source=XE; User ID=system; Password=*myPass*");
public void Open()
{
if (oraConnection.State != ConnectionState.Open)
{
oraConnection.Open();
}
}
public void Close()
{
if (oraConnection.State == ConnectionState.Open)
{
oraConnection.Close();
}}

and to execute some command like INSERT, UPDATE, or DELETE using stored procedure we can use the following method

public void ExecuteCMD(string storedProcedure, OracleParameter[] param)
{
OracleCommand oraCmd = new OracleCommand();
oraCmd,CommandType = CommandType.StoredProcedure;
oraCmd.CommandText = storedProcedure;
oraCmd.Connection = oraConnection;

if(param!=null)
{
oraCmd.Parameters.AddRange(param);
}
try
{
oraCmd.ExecuteNoneQuery();
}
catch (Exception)
{
MessageBox.Show("Sorry We've got Unknown Error","Connection Error",MessageBoxButtons.OK,MessageBoxIcon.Error);
}
}

How do I find out my root MySQL password?

Here is the best way to set your root password : Source Link Step 3 is working perfectly for me.

Commands for You

  1. sudo mysql
  2. SELECT user,authentication_string,plugin,host FROM mysql.user;
  3. ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';
  4. FLUSH PRIVILEGES;
  5. SELECT user,authentication_string,plugin,host FROM mysql.user;
  6. exit

Now you can use the Password for the root user is 'password' :

  1. mysql -u root -p
  2. CREATE USER 'sammy'@'localhost' IDENTIFIED BY 'password';
  3. GRANT ALL PRIVILEGES ON . TO 'sammy'@'localhost' WITH GRANT OPTION;
  4. FLUSH PRIVILEGES;
  5. exit

Test your MySQL Service and Version:

systemctl status mysql.service
sudo mysqladmin -p -u root version

How to call a .NET Webservice from Android using KSOAP2?

You can Use below code to call the web service and get response .Make sure that your Web Service return the response in Data Table Format..This code help you if you using data from SQL Server database .If you you using MYSQL you need to change one thing just replace word NewDataSet from sentence obj2=(SoapObject) obj1.getProperty("NewDataSet"); by DocumentElement

private static final String NAMESPACE = "http://tempuri.org/";
private static final String URL = "http://localhost/Web_Service.asmx?"; // you can use   IP address instead of localhost
private static final String METHOD_NAME = "Function_Name";
private static final String SOAP_ACTION = NAMESPACE + METHOD_NAME;

SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);
request.addProperty("parm_name", prm_value); // Parameter for Method
SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
envelope.dotNet = true;
envelope.setOutputSoapObject(request);
HttpTransportSE androidHttpTransport = new HttpTransportSE(URL);

try {
    androidHttpTransport.call(SOAP_ACTION, envelope); //call the eb service Method
} catch (Exception e) {
    e.printStackTrace();
} //Next task is to get Response and format that response

SoapObject obj, obj1, obj2, obj3;
obj = (SoapObject) envelope.getResponse();
obj1 = (SoapObject) obj.getProperty("diffgram");
obj2 = (SoapObject) obj1.getProperty("NewDataSet");

for (int i = 0; i < obj2.getPropertyCount(); i++) //the method getPropertyCount() return the number of rows
{
    obj3 = (SoapObject) obj2.getProperty(i);
    obj3.getProperty(0).toString(); //value of column 1
    obj3.getProperty(1).toString(); //value of column 2
    //like that you will get value from each column
}

If you have any problem regarding this you can write me..

Get original URL referer with PHP?

Using Cookie as a repository of reference page is much better in most cases, as cookies will keep referrer until the browser is closed (and will keep it even if browser tab is closed), so in case if user left the page open, let's say before weekends, and returned to it after a couple of days, your session will probably be expired, but cookies are still will be there.

Put that code at the begin of a page (before any html output, as cookies will be properly set only before any echo/print):

if(!isset($_COOKIE['origin_ref']))
{
    setcookie('origin_ref', $_SERVER['HTTP_REFERER']);
}

Then you can access it later:

$var = $_COOKIE['origin_ref'];

And to addition to what @pcp suggested about escaping $_SERVER['HTTP_REFERER'], when using cookie, you may also want to escape $_COOKIE['origin_ref'] on each request.

Dynamically load a function from a DLL

LoadLibrary does not do what you think it does. It loads the DLL into the memory of the current process, but it does not magically import functions defined in it! This wouldn't be possible, as function calls are resolved by the linker at compile time while LoadLibrary is called at runtime (remember that C++ is a statically typed language).

You need a separate WinAPI function to get the address of dynamically loaded functions: GetProcAddress.

Example

#include <windows.h>
#include <iostream>

/* Define a function pointer for our imported
 * function.
 * This reads as "introduce the new type f_funci as the type: 
 *                pointer to a function returning an int and 
 *                taking no arguments.
 *
 * Make sure to use matching calling convention (__cdecl, __stdcall, ...)
 * with the exported function. __stdcall is the convention used by the WinAPI
 */
typedef int (__stdcall *f_funci)();

int main()
{
  HINSTANCE hGetProcIDDLL = LoadLibrary("C:\\Documents and Settings\\User\\Desktop\\test.dll");

  if (!hGetProcIDDLL) {
    std::cout << "could not load the dynamic library" << std::endl;
    return EXIT_FAILURE;
  }

  // resolve function address here
  f_funci funci = (f_funci)GetProcAddress(hGetProcIDDLL, "funci");
  if (!funci) {
    std::cout << "could not locate the function" << std::endl;
    return EXIT_FAILURE;
  }

  std::cout << "funci() returned " << funci() << std::endl;

  return EXIT_SUCCESS;
}

Also, you should export your function from the DLL correctly. This can be done like this:

int __declspec(dllexport) __stdcall funci() {
   // ...
}

As Lundin notes, it's good practice to free the handle to the library if you don't need them it longer. This will cause it to get unloaded if no other process still holds a handle to the same DLL.

How do I get a consistent byte representation of strings in C# without manually specifying an encoding?

C# to convert a string to a byte array:

public static byte[] StrToByteArray(string str)
{
   System.Text.UTF8Encoding  encoding=new System.Text.UTF8Encoding();
   return encoding.GetBytes(str);
}

How can I force a long string without any blank to be wrapped?

For word-wrap:break-word; to work for me, I had to make sure the display was set to block, and that the width was set on the element. In Safari, it had to have a p tag and the width had to be set in ex.

How to convert wstring into string?

// Embarcadero C++ Builder 

// convertion string to wstring
string str1 = "hello";
String str2 = str1;         // typedef UnicodeString String;   -> str2 contains now u"hello";

// convertion wstring to string
String str2 = u"hello";
string str1 = UTF8string(str2).c_str();   // -> str1 contains now "hello"

`getchar()` gives the same output as the input string

Strings, by C definition, are terminated by '\0'. You have no "C strings" in your program.

Your program reads characters (buffered till ENTER) from the standard input (the keyboard) and writes them back to the standard output (the screen). It does this no matter how many characters you type or for how long you do this.

To stop the program you have to indicate that the standard input has no more data (huh?? how can a keyboard have no more data?).

You simply press Ctrl+D (Unix) or Ctrl+Z (Windows) to pretend the file has reached its end.
Ctrl+D (or Ctrl+Z) are not really characters in the C sense of the word.

If you run your program with input redirection, the EOF is the actual end of file, not a make belief one
./a.out < source.c

How do I find the current executable filename?

System.Diagnostics.Process.GetCurrentProcess().MainModule.FileName

VirtualBox and vmdk vmx files

Actually, for the configuration of the machine, just open the .vmx file with a text editor (e.g. notepad, gedit, etc.). You will be able to see the OS type, memsize, ethernet.connectionType, and other settings. Then when you make your machine, just look in the text editor for the corresponding settings. When it asks for the disk, select the .vmdk disk as mentioned above.

How to define dimens.xml for every different screen size in android?

I've uploaded a simple java program which takes your project location and the dimension file you want as input. Based on that, it would output the corresponding dimension file in the console. Here's the link to it:

https://github.com/akeshwar/Dimens-for-different-screens-in-Android/blob/master/Main.java

Here's the full code for the reference:

public class Main {


    /**
     * You can change your factors here. The current factors are in accordance with the official documentation.
     */
    private static final double LDPI_FACTOR = 0.375;
    private static final double MDPI_FACTOR = 0.5;
    private static final double HDPI_FACTOR = 0.75;
    private static final double XHDPI_FACTOR = 1.0;
    private static final double XXHDPI_FACTOR = 1.5;
    private static final double XXXHDPI_FACTOR = 2.0;

    private static double factor;

    public static void main(String[] args) throws IOException {


        Scanner in = new Scanner(System.in);
        System.out.println("Enter the location of the project/module");
        String projectPath = in.nextLine();

        System.out.println("Which of the following dimension file do you want?\n1. ldpi \n2. mdpi \n3. hdpi \n4. xhdpi \n5. xxhdpi \n6. xxxhdpi");

        int dimenType = in.nextInt();

        switch (dimenType) {
            case 1: factor = LDPI_FACTOR;
                break;
            case 2: factor = MDPI_FACTOR;
                break;
            case 3: factor = HDPI_FACTOR;
                break;
            case 4: factor = XHDPI_FACTOR;
                break;
            case 5: factor = XXHDPI_FACTOR;
                break;
            case 6: factor = XXXHDPI_FACTOR;
                break;
            default:
                factor = 1.0;
        }

        //full path = "/home/akeshwar/android-sat-bothIncluded-notintegrated/code/tpr-5-5-9/princetonReview/src/main/res/values/dimens.xml"
        //location of the project or module = "/home/akeshwar/android-sat-bothIncluded-notintegrated/code/tpr-5-5-9/princetonReview/"


        /**
         * In case there is some I/O exception with the file, you can directly copy-paste the full path to the file here:
         */
        String fullPath = projectPath + "/src/main/res/values/dimens.xml";

        FileInputStream fstream = new FileInputStream(fullPath);
        BufferedReader br = new BufferedReader(new InputStreamReader(fstream));

        String strLine;

        while ((strLine = br.readLine()) != null)   {
            modifyLine(strLine);
        }
        br.close();

    }

    private static void modifyLine(String line) {

        /**
         * Well, this is how I'm detecting if the line has some dimension value or not.
         */
        if(line.contains("p</")) {
            int endIndex = line.indexOf("p</");

            //since indexOf returns the first instance of the occurring string. And, the actual dimension would follow after the first ">" in the screen
            int begIndex = line.indexOf(">");

            String prefix = line.substring(0, begIndex+1);
            String root = line.substring(begIndex+1, endIndex-1);
            String suffix = line.substring(endIndex-1,line.length());


            /**
             * Now, we have the root. We can use it to create different dimensions. Root is simply the dimension number.
             */

            double dimens = Double.parseDouble(root);
            dimens = dimens*factor*1000;
            dimens = (double)((int)dimens);
            dimens = dimens/1000;
            root = dimens + "";

            System.out.println(prefix + " " +  root + " " + suffix );

        }

        System.out.println(line);
    }
}

"Could not find acceptable representation" using spring-boot-starter-web

I too was facing a similar issue. In my case the request path was accepting mail id as path variable, so the uri looked like /some/api/[email protected]

And based on path, Spring determined the uri is to fetch some file with ".com" extension and was trying to use different media type for response then intended one. After making path variable into request param it worked for me.

Is a Java hashmap search really O(1)?

If the number of buckets (call it b) is held constant (the usual case), then lookup is actually O(n).
As n gets large, the number of elements in each bucket averages n/b. If collision resolution is done in one of the usual ways (linked list for example), then lookup is O(n/b) = O(n).

The O notation is about what happens when n gets larger and larger. It can be misleading when applied to certain algorithms, and hash tables are a case in point. We choose the number of buckets based on how many elements we're expecting to deal with. When n is about the same size as b, then lookup is roughly constant-time, but we can't call it O(1) because O is defined in terms of a limit as n ? 8.

jquery - How to determine if a div changes its height or any css attribute?

Please don't use techniques described in other answers here. They are either not working with css3 animations size changes, floating layout changes or changes that don't come from jQuery land. You can use a resize-detector, a event-based approach, that doesn't waste your CPU time.

https://github.com/marcj/css-element-queries

It contains a ResizeSensor class you can use for that purpose.

new ResizeSensor(jQuery('#mainContent'), function(){ 
    console.log('main content dimension changed');
});

Disclaimer: I wrote this library

ViewBag, ViewData and TempData

Also the scope is different between viewbag and temptdata. viewbag is based on first view (not shared between action methods) but temptdata can be shared between an action method and just one another.

Text vertical alignment in WPF TextBlock

I found I had to do it slightly different. My problem was that if I changed the font size, the text would move up in the TextBox instead of stay on the bottom with the rest of TextBoxes on the line. By changing the vert alignment from top to bottom I was able to change the font programmatically from size 20 to size 14 & back, keeping text's gravity on the bottom and keeping things neat. Here's how:

enter image description here

Check if a property exists in a class

I'm unsure of the context on why this was needed, so this may not return enough information for you but this is what I was able to do:

if(typeof(ModelName).GetProperty("Name of Property") != null)
{
//whatevver you were wanting to do.
}

In my case I'm running through properties from a form submission and also have default values to use if the entry is left blank - so I needed to know if the there was a value to use - I prefixed all my default values in the model with Default so all I needed to do is check if there was a property that started with that.

Error when using scp command "bash: scp: command not found"

Check if scp is installed or not on from where you want want to copy check using which scp

If it's already installed, it will print you a path like /usr/bin/scp Else, install scp using:

yum -y install openssh-clients

Then copy command

scp -r [email protected]:/var/www/html/database_backup/restore_fullbackup/backup_20140308-023002.sql  /var/www/html/db_bkp/

hide div tag on mobile view only?

The solution given didn't work for me on the desktop, it just showed both divs, although the mobile only showed the mobile div. So I did a little search and found the min-width option. I updated my code to the following and it works fine now :)

CSS:

    @media all and (min-width: 480px) {
    .deskContent {display:block;}
    .phoneContent {display:none;}
}

@media all and (max-width: 479px) {
    .deskContent {display:none;}
    .phoneContent {display:block;}
}

HTML:

<div class="deskContent">Content for desktop</div>
<div class="phoneContent">Content for mobile</div>

click command in selenium webdriver does not work

Please refer here https://code.google.com/p/selenium/issues/detail?id=6756 In crux

Please open the system display settings and ensure that font size is set to 100% It worked surprisingly

How can I disable a specific LI element inside a UL?

I usualy use <li> to include <a> link. I disabled click action writing like this; You may not include <a> link, then you will ignore my post.

_x000D_
_x000D_
a.noclick       {_x000D_
  pointer-events: none;_x000D_
}
_x000D_
<a class="noclick" href="#">this is disabled</a>
_x000D_
_x000D_
_x000D_

How to select rows with NaN in particular column?

Try the following:

df[df['Col2'].isnull()]

How to check if array is not empty?

I can't comment yet, but it should be mentioned that if you use numpy array with more than one element this will fail:

if l:
    print "list has items"

elif not l:
    print "list is empty"

the error will be:

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

Reading rows from a CSV file in Python

The csv module handles csv files by row. If you want to handle it by column, pandas is a good solution.

Besides, there are 2 ways to get all (or specific) columns with pure simple Python code.

1. csv.DictReader

with open('demo.csv') as file:
    data = {}
    for row in csv.DictReader(file):
        for key, value in row.items():
            if key not in data:
                data[key] = []
            data[key].append(value)

It is easy to understand.

2. csv.reader with zip

with open('demo.csv') as file:
    data = {values[0]: values[1:] for values in zip(*csv.reader(file))}

This is not very clear, but efficient.

zip(x, y, z) transpose (x, y, z), while x, y, z are lists. *csv.reader(file) make (x, y, z) for zip, with column names.

Demo Result

The content of demo.csv:

a,b,c
1,2,3
4,5,6
7,8,9

The result of 1:

>>> print(data)
{'c': ['3', '6', '9'], 'b': ['2', '5', '8'], 'a': ['1', '4', '7']}

The result of 2:

>>> print(data)
{'c': ('3', '6', '9'), 'b': ('2', '5', '8'), 'a': ('1', '4', '7')}

How can I adjust DIV width to contents

EDIT2- Yea auto fills the DOM SOZ!

#img_box{        
    width:90%;
    height:90%;
    min-width: 400px;
    min-height: 400px;
}

check out this fiddle

http://jsfiddle.net/ppumkin/4qjXv/2/

http://jsfiddle.net/ppumkin/4qjXv/3/

and this page

http://www.webmasterworld.com/css/3828593.htm

Removed original answer because it was wrong.

The width is ok- but the height resets to 0

so

 min-height: 400px;

javax.crypto.IllegalBlockSizeException : Input length must be multiple of 16 when decrypting with padded cipher

The algorithm you are using, "AES", is a shorthand for "AES/ECB/NoPadding". What this means is that you are using the AES algorithm with 128-bit key size and block size, with the ECB mode of operation and no padding.

In other words: you are only able to encrypt data in blocks of 128 bits or 16 bytes. That's why you are getting that IllegalBlockSizeException exception.

If you want to encrypt data in sizes that are not multiple of 16 bytes, you are either going to have to use some kind of padding, or a cipher-stream. For instance, you could use CBC mode (a mode of operation that effectively transforms a block cipher into a stream cipher) by specifying "AES/CBC/NoPadding" as the algorithm, or PKCS5 padding by specifying "AES/ECB/PKCS5", which will automatically add some bytes at the end of your data in a very specific format to make the size of the ciphertext multiple of 16 bytes, and in a way that the decryption algorithm will understand that it has to ignore some data.

In any case, I strongly suggest that you stop right now what you are doing and go study some very introductory material on cryptography. For instance, check Crypto I on Coursera. You should understand very well the implications of choosing one mode or another, what are their strengths and, most importantly, their weaknesses. Without this knowledge, it is very easy to build systems which are very easy to break.


Update: based on your comments on the question, don't ever encrypt passwords when storing them at a database!!!!! You should never, ever do this. You must HASH the passwords, properly salted, which is completely different from encrypting. Really, please, don't do what you are trying to do... By encrypting the passwords, they can be decrypted. What this means is that you, as the database manager and who knows the secret key, you will be able to read every password stored in your database. Either you knew this and are doing something very, very bad, or you didn't know this, and should get shocked and stop it.

Error QApplication: no such file or directory

Make sure you have qmake in your path (which qmake), and that it works (qmake -v) (IF you have to kill it with ctr-c then there is something wrong with your environment).

Then follow this: http://developer.qt.nokia.com/doc/qt-4.8/gettingstartedqt.html

Changing EditText bottom line color with appcompat v7

You can use just backgroundTint for change bottom line color of edit text

 android:backgroundTint="#000000"

example :

 <EditText
          android:id="@+id/title1"
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:backgroundTint="#000000" />

.Net picking wrong referenced assembly version

I had the same problem with different assemblies referencing different versions of Newtonsoft.json. The solution that worked for me was running update-package from Nuget Package Manager Console.

How to get the browser to navigate to URL in JavaScript

Try these:

  1. window.location.href = 'http://www.google.com';
  2. window.location.assign("http://www.w3schools.com");
  3. window.location = 'http://www.google.com';

For more see this link: other ways to reload the page with JavaScript

Send push to Android by C# using FCM (Firebase Cloud Messaging)

Based on Teste's code .. I can confirm the following works. I can't say whether or not this is "good" code, but it certainly works and could get you back up and running quickly if you ended up with GCM to FCM server problems!

public AndroidFCMPushNotificationStatus SendNotification(string serverApiKey, string senderId, string deviceId, string message)
{
    AndroidFCMPushNotificationStatus result = new AndroidFCMPushNotificationStatus();

    try
    {
        result.Successful = false;
        result.Error = null;

        var value = message;
        WebRequest tRequest = WebRequest.Create("https://fcm.googleapis.com/fcm/send");
        tRequest.Method = "post";
        tRequest.ContentType = "application/x-www-form-urlencoded;charset=UTF-8";
        tRequest.Headers.Add(string.Format("Authorization: key={0}", serverApiKey));
        tRequest.Headers.Add(string.Format("Sender: id={0}", senderId));

        string postData = "collapse_key=score_update&time_to_live=108&delay_while_idle=1&data.message=" + value + "&data.time=" + System.DateTime.Now.ToString() + "&registration_id=" + deviceId + "";

        Byte[] byteArray = Encoding.UTF8.GetBytes(postData);
        tRequest.ContentLength = byteArray.Length;

        using (Stream dataStream = tRequest.GetRequestStream())
        {
            dataStream.Write(byteArray, 0, byteArray.Length);

            using (WebResponse tResponse = tRequest.GetResponse())
            {
                using (Stream dataStreamResponse = tResponse.GetResponseStream())
                {
                    using (StreamReader tReader = new StreamReader(dataStreamResponse))
                    {
                        String sResponseFromServer = tReader.ReadToEnd();
                        result.Response = sResponseFromServer;
                    }
                }
            }
        }
    }
    catch (Exception ex)
    {
        result.Successful = false;
        result.Response = null;
        result.Error = ex;
    }

    return result;
}


public class AndroidFCMPushNotificationStatus
{
    public bool Successful
    {
        get;
        set;
    }

    public string Response
    {
        get;
        set;
    }
    public Exception Error
    {
        get;
        set;
    }
}

DIV :after - add content after DIV

Position your <div> absolutely at the bottom and don't forget to give div.A a position: relative - http://jsfiddle.net/TTaMx/

    .A {
        position: relative;
        margin: 40px 0;
        height: 40px;
        width: 200px;
        background: #eee;
    }

    .A:after {
        content: " ";
        display: block;
        background: #c00;
        height: 29px;
        width: 100%;

        position: absolute;
        bottom: -29px;
    }?

Binding value to style

Turns out the binding of style to a string doesn't work. The solution would be to bind the background of the style.

 <div class="circle" [style.background]="color">

XPath to select multiple tags

One correct answer is:

/a/b/*[self::c or self::d or self::e]

Do note that this

a/b/*[local-name()='c' or local-name()='d' or local-name()='e']

is both too-long and incorrect. This XPath expression will select nodes like:

OhMy:c

NotWanted:d 

QuiteDifferent:e

is there a require for json in node.js

No. Either use readFile or readFileSync (The latter only at startup time).

Or use an existing library like

Alternatively write your config in a js file rather then a json file like

module.exports = {
  // json
}

Finding the position of the max element

std::max_element takes two iterators delimiting a sequence and returns an iterator pointing to the maximal element in that sequence. You can additionally pass a predicate to the function that defines the ordering of elements.

Convert a string to integer with decimal in Python

"Convert" only makes sense when you change from one data type to another without loss of fidelity. The number represented by the string is a float and will lose precision upon being forced into an int.

You want to round instead, probably (I hope that the numbers don't represent currency because then rounding gets a whole lot more complicated).

round(float('23.45678'))

Escape double quote in grep

The problem is that you aren't correctly escaping the input string, try:

echo "\"member\":\"time\"" | grep -e "member\""

Alternatively, you can use unescaped double quotes within single quotes:

echo '"member":"time"' | grep -e 'member"'

It's a matter of preference which you find clearer, although the second approach prevents you from nesting your command within another set of single quotes (e.g. ssh 'cmd').

how to compare two string dates in javascript?

If your date is not in format standar yyyy-mm-dd (2017-02-06) for example 20/06/2016. You can use this code

var parts ='01/07/2016'.val().split('/');
var d1 = Number(parts[2] + parts[1] + parts[0]);
parts ='20/06/2016'.val().split('/');
var d2 = Number(parts[2] + parts[1] + parts[0]);
return d1 > d2

Class file for com.google.android.gms.internal.zzaja not found

I solved this exact problem today and stumbled onto this unanswered question by chance during the process.

First, ensure you've properly setup Firebase for Android as documented here: https://firebase.google.com/docs/android/setup. Then, make sure you are compiling the latest version of the Firebase APIs (9.2.0) and the Google Play Services APIs (9.2.0) that you are using. My gradle dependencies look something like this:

dependencies {
    ...
    compile 'com.google.android.gms:play-services-location:9.2.0'
    compile 'com.google.firebase:firebase-core:9.2.0'
    compile 'com.google.firebase:firebase-auth:9.2.0'
    compile 'com.google.firebase:firebase-messaging:9.2.0'
}

Hope this helps!

How to calculate percentage with a SQL statement

You need to group on the grade field. This query should give you what your looking for in pretty much any database.

    Select Grade, CountofGrade / sum(CountofGrade) *100 
    from
    (
    Select Grade, Count(*) as CountofGrade
    From Grades
    Group By Grade) as sub
    Group by Grade

You should specify the system you're using.

SQL: How do I SELECT only the rows with a unique value on certain column?

Updated to use your newly provided data:

The solutions using the original data may be found at the end of this answer.

Using your new data:

DECLARE  @T TABLE( [contract] INT, project INT, activity INT )
INSERT INTO @T VALUES( 1000,    8000,    10 )
INSERT INTO @T VALUES( 1000,    8000,    20 )
INSERT INTO @T VALUES( 1000,    8001,    10 )
INSERT INTO @T VALUES( 2000,    9000,    49 )
INSERT INTO @T VALUES( 2000,    9001,    49 )
INSERT INTO @T VALUES( 3000,    9000,    79 )
INSERT INTO @T VALUES( 3000,    9000,    78 )

SELECT DISTINCT [contract], activity FROM @T AS A WHERE
    (SELECT COUNT( DISTINCT activity ) 
     FROM @T AS B WHERE B.[contract] = A.[contract]) = 1

returns: 2000, 49

Solutions using original data

WARNING: The following solutions use the data previously given in the question and may not make sense for the current question. I have left them attached for completeness only.

SELECT Col1, Count( col1 ) AS count FROM table 
GROUP BY col1
HAVING count > 1

This should get you a list of all the values in col1 that are not distinct. You can place this in a table var or temp table and join against it.

Here is an example using a sub-query:

DECLARE @t TABLE( col1 VARCHAR(1), col2 VARCHAR(1), col3 VARCHAR(1) )

INSERT INTO @t VALUES( 'A', 'B', 'C' );
INSERT INTO @t VALUES( 'D', 'E', 'F' );
INSERT INTO @t VALUES( 'A', 'J', 'K' );
INSERT INTO @t VALUES( 'G', 'H', 'H' );

SELECT * FROM @t

SELECT col1, col2 FROM @t WHERE col1 NOT IN 
    (SELECT col1 FROM @t AS t GROUP BY col1 HAVING COUNT( col1 ) > 1)

This returns:

D   E
G   H

And another method that users a temp table and join:

DECLARE @t TABLE( col1 VARCHAR(1), col2 VARCHAR(1), col3 VARCHAR(1) )

INSERT INTO @t VALUES( 'A', 'B', 'C' );
INSERT INTO @t VALUES( 'D', 'E', 'F' );
INSERT INTO @t VALUES( 'A', 'J', 'K' );
INSERT INTO @t VALUES( 'G', 'H', 'H' );

SELECT * FROM @t

DROP TABLE #temp_table  
SELECT col1 INTO #temp_table
    FROM @t AS t GROUP BY col1 HAVING COUNT( col1 ) = 1

SELECT t.col1, t.col2 FROM @t AS t
    INNER JOIN #temp_table AS tt ON t.col1 = tt.col1

Also returns:

D   E
G   H

How to change Label Value using javascript

hope this help someone else : use innerHTML for using label object.

  document.getElementById('lableObject').innerHTML = res.FullName;

How do you grep a file and get the next 5 lines

Some awk version.

awk '/19:55/{c=5} c-->0'
awk '/19:55/{c=5} c && c--'

When pattern found, set c=5
If c is true, print and decrease number of c

Java get month string from integer

DateFormatSymbols class provides methods for our ease use.

To get short month strings. For example: "Jan", "Feb", etc.

getShortMonths()

To get month strings. For example: "January", "February", etc.

getMonths()

Sample code to return month string in mmm format,

private static String getShortMonthFromNumber(int month){
    if(month<0 || month>11){
        return "";
    }
    return new DateFormatSymbols().getShortMonths()[month];
}

How do you access the element HTML from within an Angular attribute directive?

This is because the content of

<p myHighlight>Highlight me!</p>

has not been rendered when the constructor of the HighlightDirective is called so there is no content yet.

If you implement the AfterContentInit hook you will get the element and its content.

import { Directive, ElementRef, AfterContentInit } from '@angular/core';

@Directive({ selector: '[myHighlight]' })

export class HighlightDirective {

    constructor(private el: ElementRef) {
        //el.nativeElement.style.backgroundColor = 'yellow';
    }

    ngAfterContentInit(){
        //you can get to the element content here 
        //this.el.nativeElement
    }
}

Print the data in ResultSet along with column names

use further as

rs.getString(1);
rs.getInt(2);

1, 2 is the column number of table and set int or string as per data-type of coloumn

How to check if a column is empty or null using SQL query select statement?

Here is my preferred way to check for "if null or empty":

SELECT * 
FROM UserProfile 
WHERE PropertydefinitionID in (40, 53) 
AND NULLIF(PropertyValue, '') is null

Since it modifies the search argument (SARG) it might have performance issues because it might not use an existing index on the PropertyValue column.

How can I easily convert DataReader to List<T>?

I know this question is old, and already answered, but...

Since SqlDataReader already implements IEnumerable, why is there a need to create a loop over the records?

I've been using the method below without any issues, nor without any performance issues: So far I have tested with IList, List(Of T), IEnumerable, IEnumerable(Of T), IQueryable, and IQueryable(Of T)

Imports System.Data.SqlClient
Imports System.Data
Imports System.Threading.Tasks

Public Class DataAccess
Implements IDisposable

#Region "   Properties  "

''' <summary>
''' Set the Query Type
''' </summary>
''' <value></value>
''' <remarks></remarks>
Public WriteOnly Property QueryType() As CmdType
    Set(ByVal value As CmdType)
        _QT = value
    End Set
End Property
Private _QT As CmdType

''' <summary>
''' Set the query to run
''' </summary>
''' <value></value>
''' <remarks></remarks>
Public WriteOnly Property Query() As String
    Set(ByVal value As String)
        _Qry = value
    End Set
End Property
Private _Qry As String

''' <summary>
''' Set the parameter names
''' </summary>
''' <value></value>
''' <remarks></remarks>
Public WriteOnly Property ParameterNames() As Object
    Set(ByVal value As Object)
        _PNs = value
    End Set
End Property
Private _PNs As Object

''' <summary>
''' Set the parameter values
''' </summary>
''' <value></value>
''' <remarks></remarks>
Public WriteOnly Property ParameterValues() As Object
    Set(ByVal value As Object)
        _PVs = value
    End Set
End Property
Private _PVs As Object

''' <summary>
''' Set the parameter data type
''' </summary>
''' <value></value>
''' <remarks></remarks>
Public WriteOnly Property ParameterDataTypes() As DataType()
    Set(ByVal value As DataType())
        _DTs = value
    End Set
End Property
Private _DTs As DataType()

''' <summary>
''' Check if there are parameters, before setting them
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Private ReadOnly Property AreParams() As Boolean
    Get
        If (IsArray(_PVs) And IsArray(_PNs)) Then
            If (_PVs.GetUpperBound(0) = _PNs.GetUpperBound(0)) Then
                Return True
            Else
                Return False
            End If
        Else
            Return False
        End If
    End Get
End Property

''' <summary>
''' Set our dynamic connection string
''' </summary>
''' <value></value>
''' <returns></returns>
''' <remarks></remarks>
Private ReadOnly Property _ConnString() As String
    Get
        If System.Diagnostics.Debugger.IsAttached OrElse My.Settings.AttachToBeta OrElse Not (Common.CheckPaid) Then
            Return My.Settings.DevConnString
        Else
            Return My.Settings.TurboKitsv2ConnectionString
        End If
    End Get
End Property

Private _Rdr As SqlDataReader
Private _Conn As SqlConnection
Private _Cmd As SqlCommand

#End Region

#Region "   Methods "

''' <summary>
''' Fire us up!
''' </summary>
''' <remarks></remarks>
Public Sub New()
    Parallel.Invoke(Sub()
                        _Conn = New SqlConnection(_ConnString)
                    End Sub,
                    Sub()
                        _Cmd = New SqlCommand
                    End Sub)
End Sub

''' <summary>
''' Get our results
''' </summary>
''' <returns></returns>
''' <remarks></remarks>
Public Function GetResults() As SqlDataReader
    Try
        Parallel.Invoke(Sub()
                            If AreParams Then
                                PrepareParams(_Cmd)
                            End If
                            _Cmd.Connection = _Conn
                            _Cmd.CommandType = _QT
                            _Cmd.CommandText = _Qry
                            _Cmd.Connection.Open()
                            _Rdr = _Cmd.ExecuteReader(CommandBehavior.CloseConnection)
                        End Sub)
        If _Rdr.HasRows Then
            Return _Rdr
        Else
            Return Nothing
        End If
    Catch sEx As SqlException
        Return Nothing
    Catch ex As Exception
        Return Nothing
    End Try
End Function

''' <summary>
''' Prepare our parameters
''' </summary>
''' <param name="objCmd"></param>
''' <remarks></remarks>
Private Sub PrepareParams(ByVal objCmd As Object)
    Try
        Dim _DataSize As Long
        Dim _PCt As Integer = _PVs.GetUpperBound(0)

        For i As Long = 0 To _PCt
            If IsArray(_DTs) Then
                Select Case _DTs(i)
                    Case 0, 33, 6, 9, 13, 19
                        _DataSize = 8
                    Case 1, 3, 7, 10, 12, 21, 22, 23, 25
                        _DataSize = Len(_PVs(i))
                    Case 2, 20
                        _DataSize = 1
                    Case 5
                        _DataSize = 17
                    Case 8, 17, 15
                        _DataSize = 4
                    Case 14
                        _DataSize = 16
                    Case 31
                        _DataSize = 3
                    Case 32
                        _DataSize = 5
                    Case 16
                        _DataSize = 2
                    Case 15
                End Select
                objCmd.Parameters.Add(_PNs(i), _DTs(i), _DataSize).Value = _PVs(i)
            Else
                objCmd.Parameters.AddWithValue(_PNs(i), _PVs(i))
            End If
        Next
    Catch ex As Exception
    End Try
End Sub

#End Region

#Region "IDisposable Support"

Private disposedValue As Boolean ' To detect redundant calls

' IDisposable
Protected Overridable Sub Dispose(ByVal disposing As Boolean)
    If Not Me.disposedValue Then
        If disposing Then
        End If
        Try
            Erase _PNs : Erase _PVs : Erase _DTs
            _Qry = String.Empty
            _Rdr.Close()
            _Rdr.Dispose()
            _Cmd.Parameters.Clear()
            _Cmd.Connection.Close()
            _Conn.Close()
            _Cmd.Dispose()
            _Conn.Dispose()
        Catch ex As Exception

        End Try
    End If
    Me.disposedValue = True
End Sub

' TODO: override Finalize() only if Dispose(ByVal disposing As Boolean) above has code to free unmanaged resources.
Protected Overrides Sub Finalize()
    ' Do not change this code.  Put cleanup code in Dispose(ByVal disposing As Boolean) above.
    Dispose(False)
    MyBase.Finalize()
End Sub

' This code added by Visual Basic to correctly implement the disposable pattern.
Public Sub Dispose() Implements IDisposable.Dispose
    ' Do not change this code.  Put cleanup code in Dispose(ByVal disposing As Boolean) above.
    Dispose(True)
    GC.SuppressFinalize(Me)
End Sub

#End Region

End Class

Strong Typing Class

Public Class OrderDCTyping
    Public Property OrderID As Long = 0
    Public Property OrderTrackingNumber As String = String.Empty
    Public Property OrderShipped As Boolean = False
    Public Property OrderShippedOn As Date = Nothing
    Public Property OrderPaid As Boolean = False
    Public Property OrderPaidOn As Date = Nothing
    Public Property TransactionID As String
End Class

Usage

Public Function GetCurrentOrders() As IEnumerable(Of OrderDCTyping)
    Try
        Using db As New DataAccess
            With db
                .QueryType = CmdType.StoredProcedure
                .Query = "[Desktop].[CurrentOrders]"
                Using _Results = .GetResults()
                    If _Results IsNot Nothing Then
                        _Qry = (From row In _Results.Cast(Of DbDataRecord)()
                                    Select New OrderDCTyping() With {
                                        .OrderID = Common.IsNull(Of Long)(row, 0, 0),
                                        .OrderTrackingNumber = Common.IsNull(Of String)(row, 1, String.Empty),
                                        .OrderShipped = Common.IsNull(Of Boolean)(row, 2, False),
                                        .OrderShippedOn = Common.IsNull(Of Date)(row, 3, Nothing),
                                        .OrderPaid = Common.IsNull(Of Boolean)(row, 4, False),
                                        .OrderPaidOn = Common.IsNull(Of Date)(row, 5, Nothing),
                                        .TransactionID = Common.IsNull(Of String)(row, 6, String.Empty)
                                    }).ToList()
                    Else
                        _Qry = Nothing
                    End If
                End Using
                Return _Qry
            End With
        End Using
    Catch ex As Exception
        Return Nothing
    End Try
End Function

SQL query to find Nth highest salary from a salary table

Try this one for finding 5th highest salary-

SELECT DISTINCT(column name) FROM table ORDER BY (column name) desc LIMIT 4,1

for nth salary-

SELECT DISTINCT(column name) FROM table ORDER BY (column name) desc LIMIT n-1,1

I have tried it on phpmyadmin panel..

How can I write data in YAML format in a file?

import yaml

data = dict(
    A = 'a',
    B = dict(
        C = 'c',
        D = 'd',
        E = 'e',
    )
)

with open('data.yml', 'w') as outfile:
    yaml.dump(data, outfile, default_flow_style=False)

The default_flow_style=False parameter is necessary to produce the format you want (flow style), otherwise for nested collections it produces block style:

A: a
B: {C: c, D: d, E: e}