Programs & Examples On #Cascadingdropdown

In graphical user interfaces, a typical collection of 'drop-down lists' or 'combo-boxes' which are connected in a hierarchical fashion. A well known example is a Country-State/Province-City combination.

Spring data jpa- No bean named 'entityManagerFactory' is defined; Injection of autowired dependencies failed

I think this is related to the newer version of spring boot plus using spring data JPA just replace @Bean annotation above public LocalContainerEntityManagerFactoryBean entityManagerFactory() to @Bean(name="entityManagerFactory")

Determining the name of bean should solve the issue

How to Find Item in Dictionary Collection?

It's possible to find the element in Dictionary collection by using ContainsKey or TryGetValue as follows:

class Program
{
    protected static Dictionary<string, string> _tags = new Dictionary<string,string>();

    static void Main(string[] args)
    {
        string strValue;

        _tags.Add("101", "C#");
        _tags.Add("102", "ASP.NET");

        if (_tags.ContainsKey("101"))
        {
            strValue = _tags["101"];
            Console.WriteLine(strValue);
        }

        if (_tags.TryGetValue("101", out strValue))
        {
            Console.WriteLine(strValue);
        }
    }
}

Efficiently finding the last line in a text file

The inefficiency here is not really due to Python, but to the nature of how files are read. The only way to find the last line is to read the file in and find the line endings. However, the seek operation may be used to skip to any byte offset in the file. You can, therefore begin very close to the end of the file, and grab larger and larger chunks as needed until the last line ending is found:

from os import SEEK_END

def get_last_line(file):
  CHUNK_SIZE = 1024 # Would be good to make this the chunk size of the filesystem

  last_line = ""

  while True:
    # We grab chunks from the end of the file towards the beginning until we 
    # get a new line
    file.seek(-len(last_line) - CHUNK_SIZE, SEEK_END)
    chunk = file.read(CHUNK_SIZE)

    if not chunk:
      # The whole file is one big line
      return last_line

    if not last_line and chunk.endswith('\n'):
      # Ignore the trailing newline at the end of the file (but include it 
      # in the output).
      last_line = '\n'
      chunk = chunk[:-1]

    nl_pos = chunk.rfind('\n')
    # What's being searched for will have to be modified if you are searching
    # files with non-unix line endings.

    last_line = chunk[nl_pos + 1:] + last_line

    if nl_pos == -1:
      # The whole chunk is part of the last line.
      continue

    return last_line

JavaScript open in a new window, not tab

I may be wrong, but from what I understand, this is controlled by the user's browser preferences, and I do not believe that this can be overridden.

Serialize Class containing Dictionary member

Instead of using XmlSerializer you can use a System.Runtime.Serialization.DataContractSerializer. This can serialize dictionaries and interfaces no sweat.

Here is a link to a full example, http://theburningmonk.com/2010/05/net-tips-xml-serialize-or-deserialize-dictionary-in-csharp/

Is there a way to get element by XPath using JavaScript in Selenium WebDriver?

In Chrome Dev Tools you can run the following:

$x("some xpath")

How to finish current activity in Android

When you want start a new activity and finish the current activity you can do this:

API 11 or greater

Intent intent = new Intent(OldActivity.this, NewActivity.class);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);

API 10 or lower

Intent intent = new Intent(OldActivity.this, NewActivity.class);
intent.setFlags(IntentCompat.FLAG_ACTIVITY_NEW_TASK | IntentCompat.FLAG_ACTIVITY_CLEAR_TASK);
startActivity(intent);

I hope this can help somebody =)

How to get the Full file path from URI

The PathUtil method will be only working in below oreo and if it is oreo than it is likely to crash because in oreo we will not get the id but the entire path in data.getData() so all u need to do is create a file from uri and get its path from getPath() and split it.below is the working code:-

Uri uri = data.getData(); 
File file = new File(uri.getPath());//create path from uri
final String[] split = file.getPath().split(":");//split the path.
filePath = split[1];//assign it to a string(your choice).

The above code will work in oreo and if it is below oreo than PathUtil will work.Thanks!

String filePath=PathUtil.getPath(context,yourURI);

PathUtil.java

import android.annotation.SuppressLint; 
import android.content.ContentUris; 
import android.content.Context; 
import android.database.Cursor; 
import android.net.Uri; 
import android.os.Build; 
import android.os.Environment; 
import android.provider.DocumentsContract;
import android.provider.MediaStore;

import java.net.URISyntaxException;

/**
 * Created by Aki on 1/7/2017.
 */

public class PathUtil {
    /*
     * Gets the file path of the given Uri.
     */
    @SuppressLint("NewApi")
    public static String getPath(Context context, Uri uri) throws URISyntaxException {
        final boolean needToCheckUri = Build.VERSION.SDK_INT >= 19;
        String selection = null;
        String[] selectionArgs = null;
        // Uri is different in versions after KITKAT (Android 4.4), we need to
        // deal with different Uris.
        if (needToCheckUri && DocumentsContract.isDocumentUri(context.getApplicationContext(), uri)) {
            if (isExternalStorageDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                return Environment.getExternalStorageDirectory() + "/" + split[1];
            } else if (isDownloadsDocument(uri)) {
                final String id = DocumentsContract.getDocumentId(uri);
                uri = ContentUris.withAppendedId(
                        Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
            } else if (isMediaDocument(uri)) {
                final String docId = DocumentsContract.getDocumentId(uri);
                final String[] split = docId.split(":");
                final String type = split[0];
                if ("image".equals(type)) {
                    uri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
                } else if ("video".equals(type)) {
                    uri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
                } else if ("audio".equals(type)) {
                    uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
                }
                selection = "_id=?";
                selectionArgs = new String[]{ split[1] };
            }
        }
        if ("content".equalsIgnoreCase(uri.getScheme())) {
            String[] projection = { MediaStore.Images.Media.DATA };
            Cursor cursor = null;
            try {
                cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
                int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
                if (cursor.moveToFirst()) {
                    return cursor.getString(column_index);
                }
            } catch (Exception e) {
            }
        } else if ("file".equalsIgnoreCase(uri.getScheme())) {
            return uri.getPath();
        }
        return null;
    }


    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is ExternalStorageProvider.
     */
    public static boolean isExternalStorageDocument(Uri uri) {
        return "com.android.externalstorage.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is DownloadsProvider.
     */
    public static boolean isDownloadsDocument(Uri uri) {
        return "com.android.providers.downloads.documents".equals(uri.getAuthority());
    }

    /**
     * @param uri The Uri to check.
     * @return Whether the Uri authority is MediaProvider.
     */
    public static boolean isMediaDocument(Uri uri) {
        return "com.android.providers.media.documents".equals(uri.getAuthority());
    }
}

Which UUID version to use?

There are two different ways of generating a UUID.

If you just need a unique ID, you want a version 1 or version 4.

  • Version 1: This generates a unique ID based on a network card MAC address and a timer. These IDs are easy to predict (given one, I might be able to guess another one) and can be traced back to your network card. It's not recommended to create these.

  • Version 4: These are generated from random (or pseudo-random) numbers. If you just need to generate a UUID, this is probably what you want.

If you need to always generate the same UUID from a given name, you want a version 3 or version 5.

  • Version 3: This generates a unique ID from an MD5 hash of a namespace and name. If you need backwards compatibility (with another system that generates UUIDs from names), use this.

  • Version 5: This generates a unique ID from an SHA-1 hash of a namespace and name. This is the preferred version.

How do I hide the bullets on my list for the sidebar?

You have a selector ul on line 252 which is setting list-style: square outside none (a square bullet). You'll have to change it to list-style: none or just remove the line.

If you only want to remove the bullets from that specific instance, you can use the specific selector for that list and its items as follows:

ul#groups-list.items-list { list-style: none }

EditText, inputType values (xml)

Supplemental answer

Here is how the standard keyboard behaves for each of these input types.

enter image description here

See this answer for more details.

what does -zxvf mean in tar -zxvf <filename>?

  • z means (un)z_ip.
  • x means ex_tract files from the archive.
  • v means print the filenames v_erbosely.
  • f means the following argument is a f_ilename.

For more details, see tar's man page.

How to auto generate migrations with Sequelize CLI from Sequelize models?

It's 2020 and many of these answers no longer apply to the Sequelize v4/v5/v6 ecosystem.

The one good answer says to use sequelize-auto-migrations, but probably is not prescriptive enough to use in your project. So here's a bit more color...

Setup

My team uses a fork of sequelize-auto-migrations because the original repo is has not been merged a few critical PRs. #56 #57 #58 #59

$ yarn add github:scimonster/sequelize-auto-migrations#a063aa6535a3f580623581bf866cef2d609531ba

Edit package.json:

"scripts": {
  ...
  "db:makemigrations": "./node_modules/sequelize-auto-migrations/bin/makemigration.js",
  ...
}

Process

Note: Make sure you’re using git (or some source control) and database backups so that you can undo these changes if something goes really bad.

  1. Delete all old migrations if any exist.
  2. Turn off .sync()
  3. Create a mega-migration that migrates everything in your current models (yarn db:makemigrations --name "mega-migration").
  4. Commit your 01-mega-migration.js and the _current.json that is generated.
  5. if you've previously run .sync() or hand-written migrations, you need to “Fake” that mega-migration by inserting the name of it into your SequelizeMeta table. INSERT INTO SequelizeMeta Values ('01-mega-migration.js').
  6. Now you should be able to use this as normal…
  7. Make changes to your models (add/remove columns, change constraints)
  8. Run $ yarn db:makemigrations --name whatever
  9. Commit your 02-whatever.js migration and the changes to _current.json, and _current.bak.json.
  10. Run your migration through the normal sequelize-cli: $ yarn sequelize db:migrate.
  11. Repeat 7-10 as necessary

Known Gotchas

  1. Renaming a column will turn into a pair of removeColumn and addColumn. This will lose data in production. You will need to modify the up and down actions to use renameColumn instead.

For those who confused how to use renameColumn, the snippet would look like this. (switch "column_name_before" and "column_name_after" for the rollbackCommands)

{
    fn: "renameColumn",
    params: [
        "table_name",
        "column_name_before",
        "column_name_after",
        {
            transaction: transaction
        }
    ]
}
  1. If you have a lot of migrations, the down action may not perfectly remove items in an order consistent way.

  2. The maintainer of this library does not actively check it. So if it doesn't work for you out of the box, you will need to find a different community fork or another solution.

How can I set the color of a selected row in DataGrid

I've tried ControlBrushKey but it didn't work for unselected rows. The background for the unselected row was still white. But I've managed to find out that I have to override the rowstyle.

<DataGrid x:Name="pbSelectionDataGrid" Height="201" Margin="10,0"
          FontSize="20" SelectionMode="Single" FontWeight="Bold">
    <DataGrid.Resources>
        <SolidColorBrush x:Key="{x:Static SystemColors.HighlightBrushKey}" Color="#FFFDD47C"/>
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlBrushKey}" Color="#FFA6E09C"/>
        <SolidColorBrush x:Key="{x:Static SystemColors.HighlightTextBrushKey}" Color="Red"/>
        <SolidColorBrush x:Key="{x:Static SystemColors.ControlTextBrushKey}" Color="Violet"/>
    </DataGrid.Resources>
    <DataGrid.RowStyle>
        <Style TargetType="DataGridRow">
            <Setter Property="Background" Value="LightBlue" />
        </Style>
    </DataGrid.RowStyle>
</DataGrid>

SVG Positioning

There is a shorter alternative to the previous answer. SVG Elements can also be grouped by nesting svg elements:

<svg xmlns="http://www.w3.org/2000/svg"
  xmlns:xlink="http://www.w3.org/1999/xlink">
  <svg x="10">
    <rect x="10" y="10" height="100" width="100" style="stroke:#ff0000;fill: #0000ff"/>
  </svg>
  <svg x="200">
    <rect x="10" y="10" height="100" width="100" style="stroke:#009900;fill: #00cc00"/>
  </svg>
</svg>

The two rectangles are identical (apart from the colors), but the parent svg elements have different x values.

See http://tutorials.jenkov.com/svg/svg-element.html.

How to pass a function as a parameter in Java?

Java does not (yet) support closures. But there are other languages like Scala and Groovy which run in the JVM and do support closures.

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

You can do this as:

WITH abc AS( select
             FROM ...)
, XYZ AS(select
         From abc ....) /*This one uses "abc" multiple times*/
  Select 
  From XYZ....   /*using abc, XYZ multiple times*/

How to hide elements without having them take space on the page?

here's a different take on putting them back after display:none. don't use display:block/inline etc. Instead (if using javascript) set css property display to '' (i.e. blank)

How to access SOAP services from iPhone

One word: Don't.

OK obviously that isn't a real answer. But still SOAP should be avoided at all costs. ;-) Is it possible to add a proxy server between the iPhone and the web service? Perhaps something that converts REST into SOAP for you?

You could try CSOAP, a SOAP library that depends on libxml2 (which is included in the iPhone SDK).

I've written my own SOAP framework for OSX. However it is not actively maintained and will require some time to port to the iPhone (you'll need to replace NSXML with TouchXML for a start)

How to get first and last day of week in Oracle?

SELECT NEXT_DAY (TO_DATE ('01/01/'||SUBSTR('201118',1,4),'MM/DD/YYYY')+(TO_NUMBER(SUBSTR('201118',5,2))*7)-3,'SUNDAY')-7 first_day_wk,
    NEXT_DAY (TO_DATE ('01/01/'||SUBSTR('201118',1,4),'MM/DD/YYYY')+(TO_NUMBER(SUBSTR('201118',5,2))*7)-3,'SATURDAY') last_day_wk FROM dual

What are file descriptors, explained in simple terms?

A file descriptor is an opaque handle that is used in the interface between user and kernel space to identify file/socket resources. Therefore, when you use open() or socket() (system calls to interface to the kernel), you are given a file descriptor, which is an integer (it is actually an index into the processes u structure - but that is not important). Therefore, if you want to interface directly with the kernel, using system calls to read(), write(), close() etc. the handle you use is a file descriptor.

There is a layer of abstraction overlaid on the system calls, which is the stdio interface. This provides more functionality/features than the basic system calls do. For this interface, the opaque handle you get is a FILE*, which is returned by the fopen() call. There are many many functions that use the stdio interface fprintf(), fscanf(), fclose(), which are there to make your life easier. In C, stdin, stdout, and stderr are FILE*, which in UNIX respectively map to file descriptors 0, 1 and 2.

What is the purpose of Android's <merge> tag in XML layouts?

<merge/> is useful because it can get rid of unneeded ViewGroups, i.e. layouts that are simply used to wrap other views and serve no purpose themselves.

For example, if you were to <include/> a layout from another file without using merge, the two files might look something like this:

layout1.xml:

<FrameLayout>
   <include layout="@layout/layout2"/>
</FrameLayout>

layout2.xml:

<FrameLayout>
   <TextView />
   <TextView />
</FrameLayout>

which is functionally equivalent to this single layout:

<FrameLayout>
   <FrameLayout>
      <TextView />
      <TextView />
   </FrameLayout>
</FrameLayout>

That FrameLayout in layout2.xml may not be useful. <merge/> helps get rid of it. Here's what it looks like using merge (layout1.xml doesn't change):

layout2.xml:

<merge>
   <TextView />
   <TextView />
</merge>

This is functionally equivalent to this layout:

<FrameLayout>
   <TextView />
   <TextView />
</FrameLayout>

but since you are using <include/> you can reuse the layout elsewhere. It doesn't have to be used to replace only FrameLayouts - you can use it to replace any layout that isn't adding something useful to the way your view looks/behaves.

How to delete items from a dictionary while iterating over it?

You could also do it in two steps:

remove = [k for k in mydict if k == val]
for k in remove: del mydict[k]

My favorite approach is usually to just make a new dict:

# Python 2.7 and 3.x
mydict = { k:v for k,v in mydict.items() if k!=val }
# before Python 2.7
mydict = dict((k,v) for k,v in mydict.iteritems() if k!=val)

Check if string ends with certain pattern

Of course you can use the StringTokenizer class to split the String with '.' or '/', and check if the last word is "work".

Remove final character from string

What you are trying to do is an extension of string slicing in Python:

Say all strings are of length 10, last char to be removed:

>>> st[:9]
'abcdefghi'

To remove last N characters:

>>> N = 3
>>> st[:-N]
'abcdefg'

jQuery remove all list items from an unordered list

An example using .remove():

<p>Remove LI's from list</p>
<ul>
    <li>Test</li>
    <li>Test</li>
    <li>Test</li>
    <li>Test</li>
    <li>Test</li>
</ul>
<p>END</p>

setTimeout(function(){$('ul li').remove();},1000);

http://jsfiddle.net/userdude/ZAd2Y/

Also, .empty() should have worked.

How to count no of lines in text file and store the value into a variable using batch script?

Inspired by the previous posts, a shorter way of doing so:

CMD.exe
C:\>FINDSTR /R /N "^.*$" file.txt | FIND /C ":"

The number of lines

Try it. It works in my console.

EDITED:

(the "$" sign removed)

FINDSTR /R /N "^.*" file.txt | FIND /C ":"

$ reduces the number by 1 because it is accepting the first row as Field name and then counting the number of rows.

How to Disable GUI Button in Java

You create the frame with button enable, do some test to see if btn1Cliked is true, and that's all.

Then you have the actionPerformed method that does nothing with your button. So, if you don't have any action related, your button status will never be evaluated again.

Fixed digits after decimal with f-strings

When it comes to float numbers, you can use format specifiers:

f'{value:{width}.{precision}}'

where:

  • value is any expression that evaluates to a number
  • width specifies the number of characters used in total to display, but if value needs more space than the width specifies then the additional space is used.
  • precision indicates the number of characters used after the decimal point

What you are missing is the type specifier for your decimal value. In this link, you an find the available presentation types for floating point and decimal.

Here you have some examples, using the f (Fixed point) presentation type:

# notice that it adds spaces to reach the number of characters specified by width
In [1]: f'{1 + 3 * 1.5:10.3f}'
Out[1]: '     5.500'

# notice that it uses more characters than the ones specified in width
In [2]: f'{3000 + 3 ** (1 / 2):2.1f}' 
Out[2]: '3001.7'

In [3]: f'{1.2345 + 4 ** (1 / 2):9.6f}'
Out[3]: ' 3.234500'

# omitting width but providing precision will use the required characters to display the number with the the specified decimal places
In [4]: f'{1.2345 + 3 * 2:.3f}' 
Out[4]: '7.234'

# not specifying the format will display the number with as many digits as Python calculates
In [5]: f'{1.2345 + 3 * 0.5}'
Out[5]: '2.7344999999999997'

Rails: select unique values from a column

Some answers don't take into account the OP wants a array of values

Other answers don't work well if your Model has thousands of records

That said, I think a good answer is:

    Model.uniq.select(:ratings).map(&:ratings)
    => "SELECT DISTINCT ratings FROM `models` " 

Because, first you generate a array of Model (with diminished size because of the select), then you extract the only attribute those selected models have (ratings)

How to convert JSON string into List of Java object?

I made a method to do this below called jsonArrayToObjectList. Its a handy static class that will take a filename and the file contains an array in JSON form.

 List<Items> items = jsonArrayToObjectList(
            "domain/ItemsArray.json",  Item.class);

    public static <T> List<T> jsonArrayToObjectList(String jsonFileName, Class<T> tClass) throws IOException {
        ObjectMapper mapper = new ObjectMapper();
        final File file = ResourceUtils.getFile("classpath:" + jsonFileName);
        CollectionType listType = mapper.getTypeFactory()
            .constructCollectionType(ArrayList.class, tClass);
        List<T> ts = mapper.readValue(file, listType);
        return ts;
    }

What is the Python equivalent of Matlab's tic and toc functions?

The absolute best analog of tic and toc would be to simply define them in python.

def tic():
    #Homemade version of matlab tic and toc functions
    import time
    global startTime_for_tictoc
    startTime_for_tictoc = time.time()

def toc():
    import time
    if 'startTime_for_tictoc' in globals():
        print "Elapsed time is " + str(time.time() - startTime_for_tictoc) + " seconds."
    else:
        print "Toc: start time not set"

Then you can use them as:

tic()
# do stuff
toc()

Unfinished Stubbing Detected in Mockito

For those who use com.nhaarman.mockitokotlin2.mock {}

This error occurs when, for example, we create a mock inside another mock

mock {
    on { x() } doReturn mock {
        on { y() } doReturn z()
    }
}

The solution to this is to create the child mock in a variable and use the variable in the scope of the parent mock to prevent the mock creation from being explicitly nested.

val liveDataMock = mock {
        on { y() } doReturn z()
}
mock {
    on { x() } doReturn liveDataMock
}

GL

Disable submit button on form submit

Button Code

<button id="submit" name="submit" type="submit" value="Submit">Submit</button>

Disable Button

if(When You Disable the button this Case){
 $(':input[type="submit"]').prop('disabled', true); 
}else{
 $(':input[type="submit"]').prop('disabled', false); 
}

Note: You Case may Be Multiple this time more condition may need

What does "implements" do on a class?

An interface can be thought of as just a list of method definitions (without any body). If a class wants to implement and interface, it is entering into a contract, saying that it will provide an implementation for all of the methods listed in the interface. For more information, see http://download.oracle.com/javase/tutorial/java/concepts/

javaw.exe cannot find path

Make sure to download these from here:

enter image description here

Also create PATH enviroment variable on you computer like this (if it doesn't exist already):

  1. Right click on My Computer/Computer
  2. Properties
  3. Advanced system settings (or just Advanced)
  4. Enviroment variables
  5. If PATH variable doesn't exist among "User variables" click New (Variable name: PATH, Variable value : C:\Program Files\Java\jdk1.8.0\bin; <-- please check out the right version, this may differ as Oracle keeps updating Java). ; in the end enables assignment of multiple values to PATH variable.
  6. Click OK! Done

enter image description here

To be sure that everything works, open CMD Prompt and type: java -version to check for Java version and javac to be sure that compiler responds.

enter image description here

I hope this helps. Good luck!

MySQL Trigger - Storing a SELECT in a variable

You can declare local variables in MySQL triggers, with the DECLARE syntax.

Here's an example:

DROP TABLE IF EXISTS foo;
CREATE TABLE FOO (
  i SERIAL PRIMARY KEY
);

DELIMITER //
DROP TRIGGER IF EXISTS bar //

CREATE TRIGGER bar AFTER INSERT ON foo
FOR EACH ROW BEGIN
  DECLARE x INT;
  SET x = NEW.i;
  SET @a = x; -- set user variable outside trigger
END//

DELIMITER ;

SET @a = 0;

SELECT @a; -- returns 0

INSERT INTO foo () VALUES ();

SELECT @a; -- returns 1, the value it got during the trigger

When you assign a value to a variable, you must ensure that the query returns only a single value, not a set of rows or a set of columns. For instance, if your query returns a single value in practice, it's okay but as soon as it returns more than one row, you get "ERROR 1242: Subquery returns more than 1 row".

You can use LIMIT or MAX() to make sure that the local variable is set to a single value.

CREATE TRIGGER bar AFTER INSERT ON foo
FOR EACH ROW BEGIN
  DECLARE x INT;
  SET x = (SELECT age FROM users WHERE name = 'Bill'); 
  -- ERROR 1242 if more than one row with 'Bill'
END//

CREATE TRIGGER bar AFTER INSERT ON foo
FOR EACH ROW BEGIN
  DECLARE x INT;
  SET x = (SELECT MAX(age) FROM users WHERE name = 'Bill');
  -- OK even when more than one row with 'Bill'
END//

Why are C++ inline functions in the header?

Inline Functions

In C++ a macro is nothing but inline function. SO now macros are under control of compiler.

  • Important : If we define a function inside class it will become Inline automatically

Code of Inline function is replaced at the place it is called, so it reduce the overhead of calling function.

In some cases Inlining of function can not work, Such as

  • If static variable used inside inline function.

  • If function is complicated.

  • If recursive call of function

  • If address of function taken implicitely or explicitely

Function defined outside class as below may become inline

inline int AddTwoVar(int x,int y); //This may not become inline 

inline int AddTwoVar(int x,int y) { return x + y; } // This becomes inline

Function defined inside class also become inline

// Inline SpeedMeter functions
class SpeedMeter
{
    int speed;
    public:
    int getSpeed() const { return speed; }
    void setSpeed(int varSpeed) { speed = varSpeed; }
};
int main()
{
    SpeedMeter objSM;
    objSM.setSpeed(80);
    int speedValue = A.getSpeed();
} 

Here both getSpeed and setSpeed functions will become inline

Rewrite left outer join involving multiple tables from Informix to Oracle

Write one table per join, like this:

select tab1.a,tab2.b,tab3.c,tab4.d 
from 
  table1 tab1
  inner join table2 tab2 on tab2.fg = tab1.fg
  left join table3 tab3 on tab3.xxx = tab1.xxx and tab3.desc = "XYZ"
  left join table4 tab4 on tab4.xya = tab3.xya and tab4.ss = tab3.ss
  left join table5 tab5 on tab5.dd = tab3.dd and tab5.kk = tab4.kk

Note that while my query contains actual left join, your query apparently doesn't. Since the conditions are in the where, your query should behave like inner joins. (Although I admit I don't know Informix, so maybe I'm wrong there).

The specfific Informix extension used in the question works a bit differently with regards to left joins. Apart from the exact syntax of the join itself, this is mainly in the fact that in Informix, you can specify a list of outer joined tables. These will be left outer joined, and the join conditions can be put in the where clause. Note that this is a specific extension to SQL. Informix also supports 'normal' left joins, but you can't combine the two in one query, it seems.

In Oracle this extension doesn't exist, and you can't put outer join conditions in the where clause, since the conditions will be executed regardless.

So look what happens when you move conditions to the where clause:

select tab1.a,tab2.b,tab3.c,tab4.d 
from 
  table1 tab1
  inner join table2 tab2 on tab2.fg = tab1.fg
  left join table3 tab3 on tab3.xxx = tab1.xxx
  left join table4 tab4 on tab4.xya = tab3.xya
  left join table5 tab5 on tab5.dd = tab3.dd and tab5.kk = tab4.kk
where
  tab3.desc = "XYZ" and
  tab4.ss = tab3.ss

Now, only rows will be returned for which those two conditions are true. They cannot be true when no row is found, so if there is no matching row in table3 and/or table4, or if ss is null in either of the two, one of these conditions is going to return false, and no row is returned. This effectively changed your outer join to an inner join, and as such changes the behavior significantly.

PS: left join and left outer join are the same. It means that you optionally join the second table to the first (the left one). Rows are returned if there is only data in the 'left' part of the join. In Oracle you can also right [outer] join to make not the left, but the right table the leading table. And there is and even full [outer] join to return a row if there is data in either table.

Finding which process was killed by Linux OOM killer

Try this out:

grep "Killed process" /var/log/syslog

Rebasing a Git merge commit

There are two options here.

One is to do an interactive rebase and edit the merge commit, redo the merge manually and continue the rebase.

Another is to use the --rebase-merges option on git rebase, which is described as follows from the manual:

By default, a rebase will simply drop merge commits from the todo list, and put the rebased commits into a single, linear branch. With --rebase-merges, the rebase will instead try to preserve the branching structure within the commits that are to be rebased, by recreating the merge commits. Any resolved merge conflicts or manual amendments in these merge commits will have to be resolved/re-applied manually."

SQL server query to get the list of columns in a table along with Data types, NOT NULL, and PRIMARY KEY constraints

You could use the query:

select COLUMN_NAME, DATA_TYPE, CHARACTER_MAXIMUM_LENGTH, 
       NUMERIC_PRECISION, DATETIME_PRECISION, 
       IS_NULLABLE 
from INFORMATION_SCHEMA.COLUMNS
where TABLE_NAME='TableName'

to get all the metadata you require except for the Pk information.

make: *** [ ] Error 1 error

In my case there was a static variable which was not initialized. When I initialized it, the error was removed. I don't know the logic behind it but worked for me. I know its a little late but other people with similar problem might get some help.

Remove element from JSON Object

To iterate through the keys of an object, use a for .. in loop:

for (var key in json_obj) {
    if (json_obj.hasOwnProperty(key)) {
        // do something with `key'
    }
}

To test all elements for empty children, you can use a recursive approach: iterate through all elements and recursively test their children too.

Removing a property of an object can be done by using the delete keyword:

var someObj = {
    "one": 123,
    "two": 345
};
var key = "one";
delete someObj[key];
console.log(someObj); // prints { "two": 345 }

Documentation:

What does 'Unsupported major.minor version 52.0' mean, and how do I fix it?

You don't need to change the compliance level here, or rather, you should but that's not the issue.

The code compliance ensures your code is compatible with a given Java version.

For instance, if you have a code compliance targeting Java 6, you can't use Java 7's or 8's new syntax features (e.g. the diamond, the lambdas, etc. etc.).

The actual issue here is that you are trying to compile something in a Java version that seems different from the project dependencies in the classpath.

Instead, you should check the JDK/JRE you're using to build.

In Eclipse, open the project properties and check the selected JRE in the Java build path.

If you're using custom Ant (etc.) scripts, you also want to take a look there, in case the above is not sufficient per se.

OpenSSL Command to check if a server is presenting a certificate

I was debugging an SSL issue today which resulted in the same write:errno=104 error. Eventually I found out that the reason for this behaviour was that the server required SNI (servername TLS extensions) to work correctly. Supplying the -servername option to openssl made it connect successfully:

openssl s_client -connect domain.tld:443 -servername domain.tld

Hope this helps.

Embedding VLC plugin on HTML page

I found this:

<embed type="application/x-vlc-plugin"
pluginspage="http://www.videolan.org"version="VideoLAN.VLCPlugin.2"  width="100%"        
height="100%" id="vlc" loop="yes"autoplay="yes" target="http://10.1.2.201:8000/"></embed>

I don't see that in your code anywhere.... I think that's all you need and the target would be the location of your video...

and here is more info on the vlc plugin:
http://wiki.videolan.org/Documentation%3aWebPlugin#Input_object

Another thing to check is that the address for the video file is correct....

How to make remote REST call inside Node.js? any CURL?

Warning: As of Feb 11th 2020, request is fully deprecated.

One another example - you need to install request module for that

var request = require('request');
function get_trustyou(trust_you_id, callback) {
    var options = {
        uri : 'https://api.trustyou.com/hotels/'+trust_you_id+'/seal.json',
        method : 'GET'
    }; 
    var res = '';
    request(options, function (error, response, body) {
        if (!error && response.statusCode == 200) {
            res = body;
        }
        else {
            res = 'Not Found';
        }
        callback(res);
    });
}

get_trustyou("674fa44c-1fbd-4275-aa72-a20f262372cd", function(resp){
    console.log(resp);
});

DISABLE the Horizontal Scroll

Try this one to disable width-scrolling just for body the all document just is body body{overflow-x: hidden;}

How do I group Windows Form radio buttons?

If you cannot put them into one container, then you have to write code to change checked state of each RadioButton:

private void rbDataSourceFile_CheckedChanged(object sender, EventArgs e)
{
    rbDataSourceNet.Checked = !rbDataSourceFile.Checked;
}

private void rbDataSourceNet_CheckedChanged(object sender, EventArgs e)
{
  rbDataSourceFile.Checked = !rbDataSourceNet.Checked;
}

AngularJs ReferenceError: angular is not defined

I faced similar issue due to local vs remote referencing

<script src="http://ajax.googleapis.com/ajax/libs/angularjs/1.4.3/angular.js"></script>
<script src="lib/js/ui-grid/3.0.7/ui-grid.js"></script>

As ui-grid.js is dependent on angular.js, ui-grid requires angular.js by the time its loaded. But in the above case, ui-grid.js [locally saved reference file] is loaded before angularjs was loaded [from internet],

The problem was solved if I had both angular.js and ui-grid referenced locally and as well declaring angular.js before ui-grid

<script src="lib/js/angularjs/1.4.3/angular.js"></script>
<script src="lib/js/ui-grid/3.0.7/ui-grid.js"></script>

Android: Internet connectivity change listener

This should work:

public class ConnectivityChangeActivity extends Activity {

    private BroadcastReceiver networkChangeReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            Log.d("app","Network connectivity change");
        }
    };

    @Override
    protected void onResume() {
        super.onResume();

        IntentFilter intentFilter = new IntentFilter();
        intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);
        registerReceiver(networkChangeReceiver, intentFilter);
    }

    @Override
    protected void onPause() {
        super.onPause();

        unregisterReceiver(networkChangeReceiver);
    }
}

How can I extract embedded fonts from a PDF as valid font files?

Eventually found the FontForge Windows installer package and opened the PDF through the installed program. Worked a treat, so happy.

JPA COUNT with composite primary key query not working

Use count(d.ertek) or count(d.id) instead of count(d). This can be happen when you have composite primary key at your entity.

TypeError: 'type' object is not subscriptable when indexing in to a dictionary

Normally Python throws NameError if the variable is not defined:

>>> d[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'd' is not defined

However, you've managed to stumble upon a name that already exists in Python.

Because dict is the name of a built-in type in Python you are seeing what appears to be a strange error message, but in reality it is not.

The type of dict is a type. All types are objects in Python. Thus you are actually trying to index into the type object. This is why the error message says that the "'type' object is not subscriptable."

>>> type(dict)
<type 'type'>
>>> dict[0]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'type' object is not subscriptable

Note that you can blindly assign to the dict name, but you really don't want to do that. It's just going to cause you problems later.

>>> dict = {1:'a'}
>>> type(dict)
<class 'dict'>
>>> dict[1]
'a'

The true source of the problem is that you must assign variables prior to trying to use them. If you simply reorder the statements of your question, it will almost certainly work:

d = {1: "walk1.png", 2: "walk2.png", 3: "walk3.png"}
m1 = pygame.image.load(d[1])
m2 = pygame.image.load(d[2])
m3 = pygame.image.load(d[3])
playerxy = (375,130)
window.blit(m1, (playerxy))

Override intranet compatibility mode IE8

Try this metatag:

<meta http-equiv="X-UA-Compatible" content="IE=8" />

It should force IE8 to render as IE8 Standard Mode even if "Display intranet sites in compatibility view" is checked [either for intranet or all websites],I tried it my self on IE 8.0.6

How do you get the length of a list in the JSF expression language?

You can eventually extend the EL language by using the EL Functor, which will allow you to call any Java beans methods, even with parameters...

Export SQL query data to Excel

If you're just needing to export to excel, you can use the export data wizard. Right click the database, Tasks->Export data.

How to load property file from classpath?

If you use the static method and load the properties file from the classpath folder so you can use the below code :

//load a properties file from class path, inside static method
Properties prop = new Properties();
prop.load(Classname.class.getClassLoader().getResourceAsStream("foo.properties"));

How to add local .jar file dependency to build.gradle file?

An other way:

Add library in the tree view. Right click on this one. Select menu "Add As Library". A dialog appear, let you select module. OK and it's done.

How to get cookie expiration date / creation date from javascript?

If you are using Chrome you can goto the "Resources" tab and find the item "Cookies" in the left sidebar. From there select the domain you are checking the set cookie for and it will give you a list of cookies associated with that domain, along with their expiration date.

Replacing backslashes with forward slashes with str_replace() in php

You need to escape backslash with a \

  $str = str_replace ("\\", "/", $str);

Using Auto Layout in UITableView for dynamic cell layouts & variable row heights

For iOS 8 above it's really simple:

override func viewDidLoad() {  
    super.viewDidLoad()

    self.tableView.estimatedRowHeight = 80
    self.tableView.rowHeight = UITableView.automaticDimension
}

or

func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
    return UITableView.automaticDimension
}

But for iOS 7, the key is calculate the height after autolayout:

func calculateHeightForConfiguredSizingCell(cell: GSTableViewCell) -> CGFloat {
    cell.setNeedsLayout()
    cell.layoutIfNeeded()
    let height = cell.contentView.systemLayoutSizeFittingSize(UILayoutFittingExpandedSize).height + 1.0
    return height
}

Important

  • If multiple lines labels, don't forget set the numberOfLines to 0.

  • Don't forget label.preferredMaxLayoutWidth = CGRectGetWidth(tableView.bounds)

The full example code is here.

How to hide the bar at the top of "youtube" even when mouse hovers over it?

What I did to disable the hover state of the iframe, was to use pointer-events:none in a css style. It shows the info on load, but after that hover shouldn't trigger showing the info.

Passing an array to a query using a WHERE clause

Col. Shrapnel's SafeMySQL library for PHP provides type-hinted placeholders in its parametrised queries, and includes a couple of convenient placeholders for working with arrays. The ?a placeholder expands out an array to a comma-separated list of escaped strings*.

For example:

$someArray = [1, 2, 5];
$galleries = $db->getAll("SELECT * FROM galleries WHERE id IN (?a)", $someArray);

* Note that since MySQL performs automatic type coercion, it doesn't matter that SafeMySQL will convert the ids above to strings - you'll still get the correct result.

Allow only numbers to be typed in a textbox

You also can use some HTML5 attributes, some browsers might already take advantage of them (type="number" min="0").

Whatever you do, remember to re-check your inputs on the server side: you can never assume the client-side validation has been performed.

How to redirect to logon page when session State time out is completed in asp.net mvc

I discover very simple way to redirect Login Page When session end in MVC. I have already tested it and this works without problems.

In short, I catch session end in _Layout 1 minute before and make redirection.

I try to explain everything step by step.

If we want to session end 30 minute after and redirect to loginPage see this steps:

  1. Change the web config like this (set 31 minute):

     <system.web>
        <sessionState timeout="31"></sessionState>
     </system.web>
    
  2. Add this JavaScript in _Layout (when session end 1 minute before this code makes redirect, it makes count time after user last action, not first visit on site)

    <script>
        //session end 
        var sessionTimeoutWarning = @Session.Timeout- 1;
    
        var sTimeout = parseInt(sessionTimeoutWarning) * 60 * 1000;
        setTimeout('SessionEnd()', sTimeout);
    
        function SessionEnd() {
            window.location = "/Account/LogOff";
        }
    </script>
    
  3. Here is my LogOff Action, which makes only LogOff and redirect LoginIn Page

    public ActionResult LogOff()
    {
        Session["User"] = null; //it's my session variable
        Session.Clear();
        Session.Abandon();
        FormsAuthentication.SignOut(); //you write this when you use FormsAuthentication
        return RedirectToAction("Login", "Account");
    } 
    

I hope this is a very useful code for you.

What are the differences between using the terminal on a mac vs linux?

@Michael Durrant's answer ably covers the shell itself, but the shell environment also includes the various commands you use in the shell and these are going to be similar -- but not identical -- between OS X and linux. In general, both will have the same core commands and features (especially those defined in the Posix standard), but a lot of extensions will be different.

For example, linux systems generally have a useradd command to create new users, but OS X doesn't. On OS X, you generally use the GUI to create users; if you need to create them from the command line, you use dscl (which linux doesn't have) to edit the user database (see here). (Update: starting in macOS High Sierra v10.13, you can use sysadminctl -addUser instead.)

Also, some commands they have in common will have different features and options. For example, linuxes generally include GNU sed, which uses the -r option to invoke extended regular expressions; on OS X, you'd use the -E option to get the same effect. Similarly, in linux you might use ls --color=auto to get colorized output; on macOS, the closest equivalent is ls -G.

EDIT: Another difference is that many linux commands allow options to be specified after their arguments (e.g. ls file1 file2 -l), while most OS X commands require options to come strictly first (ls -l file1 file2).

Finally, since the OS itself is different, some commands wind up behaving differently between the OSes. For example, on linux you'd probably use ifconfig to change your network configuration. On OS X, ifconfig will work (probably with slightly different syntax), but your changes are likely to be overwritten randomly by the system configuration daemon; instead you should edit the network preferences with networksetup, and then let the config daemon apply them to the live network state.

React-Native Button style not work

The React Native Button is very limited in what you can do, see; Button

It does not have a style prop, and you don't set text the "web-way" like <Button>txt</Button> but via the title property <Button title="txt" />

If you want to have more control over the appearance you should use one of the TouchableXXXX' components like TouchableOpacity They are really easy to use :-)

Retrieving data from a POST method in ASP.NET

You need to examine (put a breakpoint on / Quick Watch) the Request object in the Page_Load method of your Test.aspx.cs file.

How to pass parameters using ui-sref in ui-router to controller

I've created an example to show how to. Updated state definition would be:

  $stateProvider
    .state('home', {
      url: '/:foo?bar',
      views: {
        '': {
          templateUrl: 'tpl.home.html',
          controller: 'MainRootCtrl'

        },
        ...
      }

And this would be the controller:

.controller('MainRootCtrl', function($scope, $state, $stateParams) {
    //..
    var foo = $stateParams.foo; //getting fooVal
    var bar = $stateParams.bar; //getting barVal
    //..
    $scope.state = $state.current
    $scope.params = $stateParams; 
})

What we can see is that the state home now has url defined as:

url: '/:foo?bar',

which means, that the params in url are expected as

/fooVal?bar=barValue

These two links will correctly pass arguments into the controller:

<a ui-sref="home({foo: 'fooVal1', bar: 'barVal1'})">
<a ui-sref="home({foo: 'fooVal2', bar: 'barVal2'})">

Also, the controller does consume $stateParams instead of $stateParam.

Link to doc:

You can check it here

params : {}

There is also new, more granular setting params : {}. As we've already seen, we can declare parameters as part of url. But with params : {} configuration - we can extend this definition or even introduce paramters which are not part of the url:

.state('other', {
    url: '/other/:foo?bar',
    params: { 
        // here we define default value for foo
        // we also set squash to false, to force injecting
        // even the default value into url
        foo: {
          value: 'defaultValue',
          squash: false,
        },
        // this parameter is now array
        // we can pass more items, and expect them as []
        bar : { 
          array : true,
        },
        // this param is not part of url
        // it could be passed with $state.go or ui-sref 
        hiddenParam: 'YES',
      },
    ...

Settings available for params are described in the documentation of the $stateProvider

Below is just an extract

  • value - {object|function=}: specifies the default value for this parameter. This implicitly sets this parameter as optional...
  • array - {boolean=}: (default: false) If true, the param value will be treated as an array of values.
  • squash - {bool|string=}: squash configures how a default parameter value is represented in the URL when the current parameter value is the same as the default value.

We can call these params this way:

// hidden param cannot be passed via url
<a href="#/other/fooVal?bar=1&amp;bar=2">
// default foo is skipped
<a ui-sref="other({bar: [4,5]})">

Check it in action here

Altering column size in SQL Server

Select table--> Design--> change value in Data Type shown in following Fig.

enter image description here

Save tables design.

max(length(field)) in mysql

SELECT  name, LENGTH(name) AS mlen
FROM    mytable
ORDER BY
        mlen DESC
LIMIT 1

Linking to a specific part of a web page

Just append a # followed by the ID of the <a> tag (or other HTML tag, like a <section>) that you're trying to get to. For example, if you are trying to link to the header in this HTML:

<p>This is some content.</p>
<h2><a id="target">Some Header</a></h2>
<p>This is some more content.</p>

You could use the link <a href="http://url.to.site/index.html#target">Link</a>.

Jenkins CI: How to trigger builds on SVN commit

You can use a post-commit hook.

Put the post-commit hook script in the hooks folder, create a wget_folder in your C:\ drive, and put the wget.exe file in this folder. Add the following code in the file called post-commit.bat

SET REPOS=%1   
SET REV=%2

FOR /f "tokens=*" %%a IN (  
'svnlook uuid %REPOS%'  
) DO (  
SET UUID=%%a  
)  

FOR /f "tokens=*" %%b IN (  
'svnlook changed --revision %REV% %REPOS%'  
) DO (  
SET POST=%%b   
)

echo %REPOS% ----- 1>&2

echo %REV% -- 1>&2

echo %UUID% --1>&2

echo %POST% --1>&2

C:\wget_folder\wget ^   
    --header="Content-Type:text/plain" ^   
    --post-data="%POST%" ^   
    --output-document="-" ^   
    --timeout=2 ^     
    http://localhost:9090/job/Test/build/%UUID%/notifyCommit?rev=%REV%    

where Test = name of the job

echo is used to see the value and you can also add exit 2 at the end to know about the issue and whether the post-commit hook script is running or not.

Javascript loading CSV file into an array

This is what I used to use a csv file into an array. Couldn't get the above answers to work, but this worked for me.

$(document).ready(function() {
   "use strict";
    $.ajax({
        type: "GET",
        url: "../files/icd10List.csv",
        dataType: "text",
        success: function(data) {processData(data);}
     });
});

function processData(icd10Codes) {
    "use strict";
    var input = $.csv.toArrays(icd10Codes);
    $("#test").append(input);
}

Used the jQuery-CSV Plug-in linked above.

How can I fix MySQL error #1064?

TL;DR

Error #1064 means that MySQL can't understand your command. To fix it:

  • Read the error message. It tells you exactly where in your command MySQL got confused.

  • Examine your command. If you use a programming language to create your command, use echo, console.log(), or its equivalent to show the entire command so you can see it.

  • Check the manual. By comparing against what MySQL expected at that point, the problem is often obvious.

  • Check for reserved words. If the error occurred on an object identifier, check that it isn't a reserved word (and, if it is, ensure that it's properly quoted).

  1. Aaaagh!! What does #1064 mean?

    Error messages may look like gobbledygook, but they're (often) incredibly informative and provide sufficient detail to pinpoint what went wrong. By understanding exactly what MySQL is telling you, you can arm yourself to fix any problem of this sort in the future.

    As in many programs, MySQL errors are coded according to the type of problem that occurred. Error #1064 is a syntax error.

    • What is this "syntax" of which you speak? Is it witchcraft?

      Whilst "syntax" is a word that many programmers only encounter in the context of computers, it is in fact borrowed from wider linguistics. It refers to sentence structure: i.e. the rules of grammar; or, in other words, the rules that define what constitutes a valid sentence within the language.

      For example, the following English sentence contains a syntax error (because the indefinite article "a" must always precede a noun):

      This sentence contains syntax error a.

    • What does that have to do with MySQL?

      Whenever one issues a command to a computer, one of the very first things that it must do is "parse" that command in order to make sense of it. A "syntax error" means that the parser is unable to understand what is being asked because it does not constitute a valid command within the language: in other words, the command violates the grammar of the programming language.

      It's important to note that the computer must understand the command before it can do anything with it. Because there is a syntax error, MySQL has no idea what one is after and therefore gives up before it even looks at the database and therefore the schema or table contents are not relevant.

  2. How do I fix it?

    Obviously, one needs to determine how it is that the command violates MySQL's grammar. This may sound pretty impenetrable, but MySQL is trying really hard to help us here. All we need to do is…

    • Read the message!

      MySQL not only tells us exactly where the parser encountered the syntax error, but also makes a suggestion for fixing it. For example, consider the following SQL command:

      UPDATE my_table WHERE id=101 SET name='foo'
      

      That command yields the following error message:

      ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE id=101 SET name='foo'' at line 1

      MySQL is telling us that everything seemed fine up to the word WHERE, but then a problem was encountered. In other words, it wasn't expecting to encounter WHERE at that point.

      Messages that say ...near '' at line... simply mean that the end of command was encountered unexpectedly: that is, something else should appear before the command ends.

    • Examine the actual text of your command!

      Programmers often create SQL commands using a programming language. For example a php program might have a (wrong) line like this:

      $result = $mysqli->query("UPDATE " . $tablename ."SET name='foo' WHERE id=101");
      

      If you write this this in two lines

      $query = "UPDATE " . $tablename ."SET name='foo' WHERE id=101"
      $result = $mysqli->query($query);
      

      then you can add echo $query; or var_dump($query) to see that the query actually says

      UPDATE userSET name='foo' WHERE id=101
      

      Often you'll see your error immediately and be able to fix it.

    • Obey orders!

      MySQL is also recommending that we "check the manual that corresponds to our MySQL version for the right syntax to use". Let's do that.

      I'm using MySQL v5.6, so I'll turn to that version's manual entry for an UPDATE command. The very first thing on the page is the command's grammar (this is true for every command):

      UPDATE [LOW_PRIORITY] [IGNORE] table_reference
          SET col_name1={expr1|DEFAULT} [, col_name2={expr2|DEFAULT}] ...
          [WHERE where_condition]
          [ORDER BY ...]
          [LIMIT row_count]
      

      The manual explains how to interpret this syntax under Typographical and Syntax Conventions, but for our purposes it's enough to recognise that: clauses contained within square brackets [ and ] are optional; vertical bars | indicate alternatives; and ellipses ... denote either an omission for brevity, or that the preceding clause may be repeated.

      We already know that the parser believed everything in our command was okay prior to the WHERE keyword, or in other words up to and including the table reference. Looking at the grammar, we see that table_reference must be followed by the SET keyword: whereas in our command it was actually followed by the WHERE keyword. This explains why the parser reports that a problem was encountered at that point.

    A note of reservation

    Of course, this was a simple example. However, by following the two steps outlined above (i.e. observing exactly where in the command the parser found the grammar to be violated and comparing against the manual's description of what was expected at that point), virtually every syntax error can be readily identified.

    I say "virtually all", because there's a small class of problems that aren't quite so easy to spot—and that is where the parser believes that the language element encountered means one thing whereas you intend it to mean another. Take the following example:

    UPDATE my_table SET where='foo'
    

    Again, the parser does not expect to encounter WHERE at this point and so will raise a similar syntax error—but you hadn't intended for that where to be an SQL keyword: you had intended for it to identify a column for updating! However, as documented under Schema Object Names:

    If an identifier contains special characters or is a reserved word, you must quote it whenever you refer to it. (Exception: A reserved word that follows a period in a qualified name must be an identifier, so it need not be quoted.) Reserved words are listed at Section 9.3, “Keywords and Reserved Words”.

    [ deletia ]

    The identifier quote character is the backtick (“`”):

    mysql> SELECT * FROM `select` WHERE `select`.id > 100;

    If the ANSI_QUOTES SQL mode is enabled, it is also permissible to quote identifiers within double quotation marks:

    mysql> CREATE TABLE "test" (col INT);
    ERROR 1064: You have an error in your SQL syntax...
    mysql> SET sql_mode='ANSI_QUOTES';
    mysql> CREATE TABLE "test" (col INT);
    Query OK, 0 rows affected (0.00 sec)

How do I use WebRequest to access an SSL encrypted site using https?

This link will be of interest to you: http://msdn.microsoft.com/en-us/library/ds8bxk2a.aspx

For http connections, the WebRequest and WebResponse classes use SSL to communicate with web hosts that support SSL. The decision to use SSL is made by the WebRequest class, based on the URI it is given. If the URI begins with "https:", SSL is used; if the URI begins with "http:", an unencrypted connection is used.

How can you have SharePoint Link Lists default to opening in a new window?

The same instance for SP2010; the Links List webpart will not automatically open in a new window, rather user must manually rt click Link object and select Open in New Window.

The add/ insert Link option withkin SP2010 will allow a user to manually configure the link to open in a new window.

Maybe SP2012 release will adrress this...

Lambda expression to convert array/List of String to array/List of Integers

You can also use,

List<String> list = new ArrayList<>();
    list.add("1");
    list.add("2");
    list.add("3");

    Integer[] array = list.stream()
        .map( v -> Integer.valueOf(v))
        .toArray(Integer[]::new);

Where does the iPhone Simulator store its data?

For react-native users who don't use Xcode often, you can just use find. Open a terminal and search by with the database name.

$ find ~/Library/Developer -name 'myname.db'

If you don't know the exact name you can use wildcards:

$ find ~/Library/Developer -name 'myname.*'

How to see if an object is an array without using reflection?

One can access each element of an array separately using the following code:

Object o=...;
if ( o.getClass().isArray() ) {
    for(int i=0; i<Array.getLength(o); i++){
        System.out.println(Array.get(o, i));
    }
}

Notice that it is unnecessary to know what kind of underlying array it is, as this will work for any array.

Python OpenCV2 (cv2) wrapper to get image size?

cv2 uses numpy for manipulating images, so the proper and best way to get the size of an image is using numpy.shape. Assuming you are working with BGR images, here is an example:

>>> import numpy as np
>>> import cv2
>>> img = cv2.imread('foo.jpg')
>>> height, width, channels = img.shape
>>> print height, width, channels
  600 800 3

In case you were working with binary images, img will have two dimensions, and therefore you must change the code to: height, width = img.shape

How to scroll to top of the page in AngularJS?

Ideally we should do it from either controller or directive as per applicable. Use $anchorScroll, $location as dependency injection.

Then call this two method as

$location.hash('scrollToDivID');
$anchorScroll();

Here scrollToDivID is the id where you want to scroll.

Assumed you want to navigate to a error message div as

<div id='scrollToDivID'>Your Error Message</div>

For more information please see this documentation

AngularJS $http, CORS and http authentication

No you don't have to put credentials, You have to put headers on client side eg:

 $http({
        url: 'url of service',
        method: "POST",
        data: {test :  name },
        withCredentials: true,
        headers: {
                    'Content-Type': 'application/json; charset=utf-8'
        }
    });

And and on server side you have to put headers to this is example for nodejs:

/**
 * On all requests add headers
 */
app.all('*', function(req, res,next) {


    /**
     * Response settings
     * @type {Object}
     */
    var responseSettings = {
        "AccessControlAllowOrigin": req.headers.origin,
        "AccessControlAllowHeaders": "Content-Type,X-CSRF-Token, X-Requested-With, Accept, Accept-Version, Content-Length, Content-MD5,  Date, X-Api-Version, X-File-Name",
        "AccessControlAllowMethods": "POST, GET, PUT, DELETE, OPTIONS",
        "AccessControlAllowCredentials": true
    };

    /**
     * Headers
     */
    res.header("Access-Control-Allow-Credentials", responseSettings.AccessControlAllowCredentials);
    res.header("Access-Control-Allow-Origin",  responseSettings.AccessControlAllowOrigin);
    res.header("Access-Control-Allow-Headers", (req.headers['access-control-request-headers']) ? req.headers['access-control-request-headers'] : "x-requested-with");
    res.header("Access-Control-Allow-Methods", (req.headers['access-control-request-method']) ? req.headers['access-control-request-method'] : responseSettings.AccessControlAllowMethods);

    if ('OPTIONS' == req.method) {
        res.send(200);
    }
    else {
        next();
    }


});

jQuery show/hide not working

if (grid.selectedKeyNames().length > 0) {
            $('#btnRemoveFromList').show();
        } else {
            $('#btnRemoveFromList').hide();
        }

}

() - calls the method

no parentheses - returns the property

How to create a temporary directory/folder in Java?

This is what I decided to do for my own code:

/**
 * Create a new temporary directory. Use something like
 * {@link #recursiveDelete(File)} to clean this directory up since it isn't
 * deleted automatically
 * @return  the new directory
 * @throws IOException if there is an error creating the temporary directory
 */
public static File createTempDir() throws IOException
{
    final File sysTempDir = new File(System.getProperty("java.io.tmpdir"));
    File newTempDir;
    final int maxAttempts = 9;
    int attemptCount = 0;
    do
    {
        attemptCount++;
        if(attemptCount > maxAttempts)
        {
            throw new IOException(
                    "The highly improbable has occurred! Failed to " +
                    "create a unique temporary directory after " +
                    maxAttempts + " attempts.");
        }
        String dirName = UUID.randomUUID().toString();
        newTempDir = new File(sysTempDir, dirName);
    } while(newTempDir.exists());

    if(newTempDir.mkdirs())
    {
        return newTempDir;
    }
    else
    {
        throw new IOException(
                "Failed to create temp dir named " +
                newTempDir.getAbsolutePath());
    }
}

/**
 * Recursively delete file or directory
 * @param fileOrDir
 *          the file or dir to delete
 * @return
 *          true iff all files are successfully deleted
 */
public static boolean recursiveDelete(File fileOrDir)
{
    if(fileOrDir.isDirectory())
    {
        // recursively delete contents
        for(File innerFile: fileOrDir.listFiles())
        {
            if(!FileUtilities.recursiveDelete(innerFile))
            {
                return false;
            }
        }
    }

    return fileOrDir.delete();
}

Java 8 lambda get and remove element from list

To Remove element from the list

objectA.removeIf(x -> conditions);

eg:

objectA.removeIf(x -> blockedWorkerIds.contains(x));

List<String> str1 = new ArrayList<String>();
str1.add("A");
str1.add("B");
str1.add("C");
str1.add("D");

List<String> str2 = new ArrayList<String>();
str2.add("D");
str2.add("E");

str1.removeIf(x -> str2.contains(x)); 

str1.forEach(System.out::println);

OUTPUT: A B C

Oracle - Insert New Row with Auto Incremental ID

SQL trigger for automatic date generation in oracle table:

CREATE OR REPLACE TRIGGER name_of_trigger

BEFORE INSERT

ON table_name

REFERENCING NEW AS NEW

FOR EACH ROW

BEGIN

SELECT sysdate INTO :NEW.column_name FROM dual;

END;

/

What's the C++ version of Java's ArrayList

A couple of additional points re use of vector here.

Unlike ArrayList and Array in Java, you don't need to do anything special to treat a vector as an array - the underlying storage in C++ is guaranteed to be contiguous and efficiently indexable.

Unlike ArrayList, a vector can efficiently hold primitive types without encapsulation as a full-fledged object.

When removing items from a vector, be aware that the items above the removed item have to be moved down to preserve contiguous storage. This can get expensive for large containers.

Make sure if you store complex objects in the vector that their copy constructor and assignment operators are efficient. Under the covers, C++ STL uses these during container housekeeping.

Advice about reserve()ing storage upfront (ie. at vector construction or initialilzation time) to minimize memory reallocation on later extension carries over from Java to C++.

Select values from XML field in SQL Server 2008

Given that the XML field is named 'xmlField'...

SELECT 
[xmlField].value('(/person//firstName/node())[1]', 'nvarchar(max)') as FirstName,
[xmlField].value('(/person//lastName/node())[1]', 'nvarchar(max)') as LastName
FROM [myTable]

Different color for each bar in a bar chart; ChartJS

I have just got this issue recently, and here is my solution

var labels = ["001", "002", "003", "004", "005", "006", "007"];
var data = [20, 59, 80, 81, 56, 55, 40];
for (var i = 0, len = labels.length; i < len; i++) {
   background_colors.push(getRandomColor());// I use @Benjamin method here
}

var barChartData = {
  labels: labels,
  datasets: [{
    label: "My First dataset",
    fillColor: "rgba(220,220,220,0.5)", 
    strokeColor: "rgba(220,220,220,0.8)", 
    highlightFill: "rgba(220,220,220,0.75)",
    highlightStroke: "rgba(220,220,220,1)",
    backgroundColor: background_colors,
    data: data
  }]
};

In what cases do I use malloc and/or new?

Rare case to consider using malloc/free instead of new/delete is when you're allocating and then reallocating (simple pod types, not objects) using realloc as there is no similar function to realloc in C++ (although this can be done using a more C++ approach).

Can I pass variable to select statement as column name in SQL Server

You can't use variable names to bind columns or other system objects, you need dynamic sql

DECLARE @value varchar(10)  
SET @value = 'intStep'  
DECLARE @sqlText nvarchar(1000); 

SET @sqlText = N'SELECT ' + @value + ' FROM dbo.tblBatchDetail'
Exec (@sqlText)

SQL-Server: The backup set holds a backup of a database other than the existing

Same issue with me.The solution for me is:

  1. Right click on the database.
  2. Select tasks, select restore database.
  3. Click options on the left hand side.
  4. Check first option OverWrite the existing database(WITH REPLACE).
  5. Go to General, select source and destination database.
  6. Click OK, that's it

How do I use this JavaScript variable in HTML?

Try this:

<body>
    <div id="divMsg"></div>
</body>
<script>
    var name = prompt("What's your name?");
    var lengthOfName = name.length;
    document.getElementById("divMsg").innerHTML = "Length: " + lengthOfName;
</script>

How to change theme for AlertDialog

I have written an article in my blog on how to configure the layout of an AlertDialog with XML style files. The main problem is that you need different style definitions for different layout parameters. Here is a boilerplate based on the AlertDialog style of Holo Light Platform version 19 for a style file that should cover a bunch of the standard layout aspects like text sizes and background colors.

<style name="AppBaseTheme" parent="android:Theme.Holo.Light">
    ...
    <item name="android:alertDialogTheme">@style/MyAlertDialogTheme</item>
    <item name="android:alertDialogStyle">@style/MyAlertDialogStyle</item>
    ...
</style>

<style name="MyBorderlessButton">
    <!-- Set background drawable and text size of the buttons here -->
    <item name="android:background">...</item>
    <item name="android:textSize">...</item>
</style>

<style name="MyButtonBar">
    <!-- Define a background for the button bar and a divider between the buttons here -->
    <item name="android:divider">....</item>
    <item name="android:dividerPadding">...</item>
    <item name="android:showDividers">...</item>
    <item name="android:background">...</item>
</style>

<style name="MyAlertDialogTitle">
    <item name="android:maxLines">1</item>
    <item name="android:scrollHorizontally">true</item>
</style>

<style name="MyAlertTextAppearance">
    <!-- Set text size and color of title and message here -->
    <item name="android:textSize"> ... </item>
    <item name="android:textColor">...</item>
</style>

<style name="MyAlertDialogTheme">
    <item name="android:windowBackground">@android:color/transparent</item>
    <item name="android:windowTitleStyle">@style/MyAlertDialogTitle</item>
    <item name="android:windowContentOverlay">@null</item>
    <item name="android:windowMinWidthMajor">@android:dimen/dialog_min_width_major</item>
    <item name="android:windowMinWidthMinor">@android:dimen/dialog_min_width_minor</item>
    <item name="android:windowIsFloating">true</item>
    <item name="android:textAppearanceMedium">@style/MyAlertTextAppearance</item>
    <!-- If you don't want your own button bar style use
            @android:style/Holo.Light.ButtonBar.AlertDialog
            and
            ?android:attr/borderlessButtonStyle
         instead of @style/MyButtonBar and @style/MyBorderlessButton -->
    <item name="android:buttonBarStyle">@style/MyButtonBar</item>
    <item name="android:buttonBarButtonStyle">@style/MyBorderlessButton</item>
</style>

<style name="MyAlertDialogStyle">
    <!-- Define background colors of title, message, buttons, etc. here -->
    <item name="android:fullDark">...</item>
    <item name="android:topDark">...</item>
    <item name="android:centerDark">...</item>
    <item name="android:bottomDark">...</item>
    <item name="android:fullBright">...</item>
    <item name="android:topBright">...</item>
    <item name="android:centerBright">...</item>
    <item name="android:bottomBright">...</item>
    <item name="android:bottomMedium">...</item>
    <item name="android:centerMedium">...</item>
</style>

How to change the order of DataFrame columns?

Here's a way to move one existing column that will modify the existing data frame in place.

my_column = df.pop('column name')
df.insert(3, my_column.name, my_column)

What is the most robust way to force a UIView to redraw?

I had the same problem, and all the solutions from SO or Google didn't work for me. Usually, setNeedsDisplay does work, but when it doesn't...
I've tried calling setNeedsDisplay of the view just every possible way from every possible threads and stuff - still no success. We know, as Rob said, that

"this needs to be drawn in the next draw cycle."

But for some reason it wouldn't draw this time. And the only solution I've found is calling it manually after some time, to let anything that blocks the draw pass away, like this:

dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, 
                                        (int64_t)(0.005 * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void) {
    [viewToRefresh setNeedsDisplay];
});

It's a good solution if you don't need the view to redraw really often. Otherwise, if you're doing some moving (action) stuff, there is usually no problems with just calling setNeedsDisplay.

I hope it will help someone who is lost there, like I was.

How to rotate x-axis tick labels in Pandas barplot

The follows might be helpful:

# Valid font size are xx-small, x-small, small, medium, large, x-large, xx-large, larger, smaller, None

plt.xticks(
    rotation=45,
    horizontalalignment='right',
    fontweight='light',
    fontsize='medium',
)

Here is the function xticks[reference] with example and API

def xticks(ticks=None, labels=None, **kwargs):
    """
    Get or set the current tick locations and labels of the x-axis.

    Call signatures::

        locs, labels = xticks()            # Get locations and labels
        xticks(ticks, [labels], **kwargs)  # Set locations and labels

    Parameters
    ----------
    ticks : array_like
        A list of positions at which ticks should be placed. You can pass an
        empty list to disable xticks.

    labels : array_like, optional
        A list of explicit labels to place at the given *locs*.

    **kwargs
        :class:`.Text` properties can be used to control the appearance of
        the labels.

    Returns
    -------
    locs
        An array of label locations.
    labels
        A list of `.Text` objects.

    Notes
    -----
    Calling this function with no arguments (e.g. ``xticks()``) is the pyplot
    equivalent of calling `~.Axes.get_xticks` and `~.Axes.get_xticklabels` on
    the current axes.
    Calling this function with arguments is the pyplot equivalent of calling
    `~.Axes.set_xticks` and `~.Axes.set_xticklabels` on the current axes.

    Examples
    --------
    Get the current locations and labels:

        >>> locs, labels = xticks()

    Set label locations:

        >>> xticks(np.arange(0, 1, step=0.2))

    Set text labels:

        >>> xticks(np.arange(5), ('Tom', 'Dick', 'Harry', 'Sally', 'Sue'))

    Set text labels and properties:

        >>> xticks(np.arange(12), calendar.month_name[1:13], rotation=20)

    Disable xticks:

        >>> xticks([])
    """

What does it mean to "program to an interface"?

"Program to interface" means don't provide hard code right the way, meaning your code should be extended without breaking the previous functionality. Just extensions, not editing the previous code.

An error occurred while collecting items to be installed (Access is denied)

I solved the problem very easily.

Go to Control Panel -> Network and Sharing Center -> Windows Firewall -> Turn off Windows Firewall

And try to install again and see the magic :)

How to sort an object array by date property?

You could use sortBy in underscore js.

http://underscorejs.org/#sortBy

Sample:

var log = [{date: '2016-01-16T05:23:38+00:00', other: 'sample'}, 
           {date: '2016-01-13T05:23:38+00:00',other: 'sample'}, 
           {date: '2016-01-15T11:23:38+00:00', other: 'sample'}];

console.log(_.sortBy(log, 'date'));

The order of keys in dictionaries

Python 3.7+

In Python 3.7.0 the insertion-order preservation nature of dict objects has been declared to be an official part of the Python language spec. Therefore, you can depend on it.

Python 3.6 (CPython)

As of Python 3.6, for the CPython implementation of Python, dictionaries maintain insertion order by default. This is considered an implementation detail though; you should still use collections.OrderedDict if you want insertion ordering that's guaranteed across other implementations of Python.

Python >=2.7 and <3.6

Use the collections.OrderedDict class when you need a dict that remembers the order of items inserted.

grant remote access of MySQL database from any IP address

Open your mysql console and execute the following command (enter your database name,username and password):

GRANT ALL ON yourdatabasename.* TO admin@'%' IDENTIFIED BY 'yourRootPassword';

Then Execute:

FLUSH PRIVILEGES;

Open command line and open the file /etc/mysql/mysql.conf.d/mysqld.cnf using any editor with root privileges.

For example:

sudo nano /etc/mysql/mysql.conf.d/mysqld.cnf

Then comment out the below line:

bind-address = 127.0.0.1

Restart mysql to reflect the changes using command:

sudo service mysql restart

Enjoy ;)

Angular2 module has no exported member

I had the component name wrong(it is case sensitive) in either app.rounting.ts or app.module.ts.

How to install a Python module via its setup.py in Windows?

setup.py is designed to be run from the command line. You'll need to open your command prompt (In Windows 7, hold down shift while right-clicking in the directory with the setup.py file. You should be able to select "Open Command Window Here").

From the command line, you can type

python setup.py --help

...to get a list of commands. What you are looking to do is...

python setup.py install

matrix multiplication algorithm time complexity

Using linear algebra, there exist algorithms that achieve better complexity than the naive O(n3). Solvay Strassen algorithm achieves a complexity of O(n2.807) by reducing the number of multiplications required for each 2x2 sub-matrix from 8 to 7.

The fastest known matrix multiplication algorithm is Coppersmith-Winograd algorithm with a complexity of O(n2.3737). Unless the matrix is huge, these algorithms do not result in a vast difference in computation time. In practice, it is easier and faster to use parallel algorithms for matrix multiplication.

Line continue character in C#

C# will allow you to have a string split over multiple lines, the term is called verbatim literal:

string myString = @"this is a
                    test
                   to see how long my string
                   can be



                    and it can be quite long";

If you are looking for the alternative to & _ from VB, use the + to join your lines.

Centering in CSS Grid

You want this?

_x000D_
_x000D_
html,_x000D_
body {_x000D_
  margin: 0;_x000D_
  padding: 0;_x000D_
}_x000D_
_x000D_
.container {_x000D_
  display: grid;_x000D_
  grid-template-columns: 1fr 1fr;_x000D_
  grid-template-rows: 100vh;_x000D_
  grid-gap: 0px 0px;_x000D_
}_x000D_
_x000D_
.left_bg {_x000D_
  display: subgrid;_x000D_
  background-color: #3498db;_x000D_
  grid-column: 1 / 1;_x000D_
  grid-row: 1 / 1;_x000D_
  z-index: 0;_x000D_
}_x000D_
_x000D_
.right_bg {_x000D_
  display: subgrid;_x000D_
  background-color: #ecf0f1;_x000D_
  grid-column: 2 / 2;_x000D_
  grid_row: 1 / 1;_x000D_
  z-index: 0;_x000D_
}_x000D_
_x000D_
.text {_x000D_
  font-family: Raleway;_x000D_
  font-size: large;_x000D_
  text-align: center;_x000D_
}
_x000D_
<div class="container">_x000D_
  <!--everything on the page-->_x000D_
_x000D_
  <div class="left_bg">_x000D_
    <!--left background color of the page-->_x000D_
    <div class="text">_x000D_
      <!--left side text content-->_x000D_
      <p>Review my stuff</p>_x000D_
    </div>_x000D_
  </div>_x000D_
_x000D_
  <div class="right_bg">_x000D_
    <!--right background color of the page-->_x000D_
    <div class="text">_x000D_
      <!--right side text content-->_x000D_
      <p>Hire me!</p>_x000D_
    </div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

Upgrade Node.js to the latest version on Mac OS

You could install nvm and have multiple versions of Node.js installed.

curl https://raw.github.com/creationix/nvm/master/install.sh | sh
source ~/.nvm/nvm.sh

and then run:

nvm install 0.8.22  #(or whatever version of Node.js you want)

you can see what versions you have installed with :

nvm list

and you can change between versions with:

nvm use 0.8.22

The great thing about using NVM is that you can test different versions alongside one another. If different apps require different versions of Node.js, you can run them both.

CASE (Contains) rather than equal statement

CASE WHEN ', ' + dbo.Table.Column +',' LIKE '%, lactulose,%' 
  THEN 'BP Medication' ELSE '' END AS [BP Medication]

The leading ', ' and trailing ',' are added so that you can handle the match regardless of where it is in the string (first entry, last entry, or anywhere in between).

That said, why are you storing data you want to search on as a comma-separated string? This violates all kinds of forms and best practices. You should consider normalizing your schema.

In addition: don't use 'single quotes' as identifier delimiters; this syntax is deprecated. Use [square brackets] (preferred) or "double quotes" if you must. See "string literals as column aliases" here: http://msdn.microsoft.com/en-us/library/bb510662%28SQL.100%29.aspx

EDIT If you have multiple values, you can do this (you can't short-hand this with the other CASE syntax variant or by using something like IN()):

CASE 
  WHEN ', ' + dbo.Table.Column +',' LIKE '%, lactulose,%' 
  WHEN ', ' + dbo.Table.Column +',' LIKE '%, amlodipine,%' 
  THEN 'BP Medication' ELSE '' END AS [BP Medication]

If you have more values, it might be worthwhile to use a split function, e.g.

USE tempdb;
GO

CREATE FUNCTION dbo.SplitStrings(@List NVARCHAR(MAX))
RETURNS TABLE
AS
   RETURN ( SELECT DISTINCT Item FROM
       ( SELECT Item = x.i.value('(./text())[1]', 'nvarchar(max)')
         FROM ( SELECT [XML] = CONVERT(XML, '<i>'
         + REPLACE(@List,',', '</i><i>') + '</i>').query('.')
           ) AS a CROSS APPLY [XML].nodes('i') AS x(i) ) AS y
       WHERE Item IS NOT NULL
   );
GO

CREATE TABLE dbo.[Table](ID INT, [Column] VARCHAR(255));
GO

INSERT dbo.[Table] VALUES
(1,'lactulose, Lasix (furosemide), oxazepam, propranolol, rabeprazole, sertraline,'),
(2,'lactulite, Lasix (furosemide), lactulose, propranolol, rabeprazole, sertraline,'),
(3,'lactulite, Lasix (furosemide), oxazepam, propranolol, rabeprazole, sertraline,'),
(4,'lactulite, Lasix (furosemide), lactulose, amlodipine, rabeprazole, sertraline,');

SELECT t.ID
  FROM dbo.[Table] AS t
  INNER JOIN dbo.SplitStrings('lactulose,amlodipine') AS s
  ON ', ' + t.[Column] + ',' LIKE '%, ' + s.Item + ',%'
  GROUP BY t.ID;
GO

Results:

ID
----
1
2
4

Where is the php.ini file on a Linux/CentOS PC?

You can find the path to php.ini in the output of phpinfo(). See under "Loaded Configuration File".

enter image description here

Using member variable in lambda capture list inside a member function

An alternate method that limits the scope of the lambda rather than giving it access to the whole this is to pass in a local reference to the member variable, e.g.

auto& localGrid = grid;
int i;
for_each(groups.cbegin(),groups.cend(),[localGrid,&i](pair<int,set<int>> group){
            i++;
            cout<<i<<endl;
   });

How to install Anaconda on RaspBerry Pi 3 Model B

If you're interested in generalizing to different architectures, you could also run the command above and substitute uname -m in with backticks like so:

wget http://repo.continuum.io/miniconda/Miniconda3-latest-Linux-`uname -m`.sh

Get selected text from a drop-down list (select box) using jQuery

The answers posted here, for example,

$('#yourdropdownid option:selected').text();

didn't work for me, but this did:

$('#yourdropdownid').find('option:selected').text();

It is possibly an older version of jQuery.

Is there an equivalent of 'which' on the Windows command line?

TCC and TCC/LE from JPSoft are CMD.EXE replacements that add significant functionality. Relevant to the OP's question, which is a builtin command for TCC family command processors.

Can I remove the URL from my print css, so the web address doesn't print?

@media print 
{
  a[href]:after { content: none !important; }
  img[src]:after { content: none !important; }
}

How to test an Internet connection with bash?

Without ping

#!/bin/bash

wget -q --spider http://google.com

if [ $? -eq 0 ]; then
    echo "Online"
else
    echo "Offline"
fi

-q : Silence mode

--spider : don't get, just check page availability

$? : shell return code

0 : shell "All OK" code

Without wget

#!/bin/bash

echo -e "GET http://google.com HTTP/1.0\n\n" | nc google.com 80 > /dev/null 2>&1

if [ $? -eq 0 ]; then
    echo "Online"
else
    echo "Offline"
fi

What is the volatile keyword useful for?

Below is a very simple code to demonstrate the requirement of volatile for variable which is used to control the Thread execution from other thread (this is one scenario where volatile is required).

// Code to prove importance of 'volatile' when state of one thread is being mutated from another thread.
// Try running this class with and without 'volatile' for 'state' property of Task class.
public class VolatileTest {
    public static void main(String[] a) throws Exception {
        Task task = new Task();
        new Thread(task).start();

        Thread.sleep(500);
        long stoppedOn = System.nanoTime();

        task.stop(); // -----> do this to stop the thread

        System.out.println("Stopping on: " + stoppedOn);
    }
}

class Task implements Runnable {
    // Try running with and without 'volatile' here
    private volatile boolean state = true;
    private int i = 0;

    public void stop() {
        state = false;
    } 

    @Override
    public void run() {
        while(state) {
            i++;
        }
        System.out.println(i + "> Stopped on: " + System.nanoTime());
    }
}

When volatile is not used: you'll never see 'Stopped on: xxx' message even after 'Stopping on: xxx', and the program continues to run.

Stopping on: 1895303906650500

When volatile used: you'll see the 'Stopped on: xxx' immediately.

Stopping on: 1895285647980000
324565439> Stopped on: 1895285648087300

Demo: https://repl.it/repls/SilverAgonizingObjectcode

How can I use the MS JDBC driver with MS SQL Server 2008 Express?

You have the wrong URL.

I don't know what you mean by "JDBC 2005". When I looked on the microsoft site, I found something called the Microsoft SQL Server JDBC Driver 2.0. You're going to want that one - it includes lots of fixes and some perf improvements. [edit: you're probably going to want the latest driver. As of March 2012, the latest JDBC driver from Microsoft is JDBC 4.0]

Check the release notes. For this driver, you want:

URL:  jdbc:sqlserver://server:port;DatabaseName=dbname
Class name: com.microsoft.sqlserver.jdbc.SQLServerDriver

It seems you have the class name correct, but the URL wrong.

Microsoft changed the class name and the URL after its initial release of a JDBC driver. The URL you are using goes with the original JDBC driver from Microsoft, the one MS calls the "SQL Server 2000 version". But that driver uses a different classname.

For all subsequent drivers, the URL changed to the form I have here.

This is in the release notes for the JDBC driver.

How do I create a link using javascript?

Dynamically create a hyperlink with raw JavaScript:

   var anchorElem = document.createElement('a');
   anchorElem.setAttribute("href", yourLink);
   anchorElem.innerHTML = yourLinkText;

   document.body.appendChild(anchorElem); // append your new link to the body

What size do you use for varchar(MAX) in your parameter declaration?

For those of us who did not see -1 by Michal Chaniewski, the complete line of code:

cmd.Parameters.Add("@blah",SqlDbType.VarChar,-1).Value = "some large text";

CSS Input field text color of inputted text

To add color to an input, Use the following css code:

input{
     color: black;
}

Create table using Javascript

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var div = document.createElement('div');
            div.setAttribute("id", "tbl");
            document.body.appendChild(div)
                document.getElementById("tbl").innerHTML = "<table border = '1'>" +
              '<tr>' +
                '<th>Header 1</th>' +
                '<th>Header 2</th> ' +
                '<th>Header 3</th>' +
              '</tr>' +
              '<tr>' +
                '<td>Data 1</td>' +
                '<td>Data 2</td>' +
                '<td>Data 3</td>' +
              '</tr>' +
              '<tr>' +
                '<td>Data 1</td>' +
                '<td>Data 2</td>' +
                '<td>Data 3</td>' +
              '</tr>' +
              '<tr>' +
                '<td>Data 1</td>' +
                '<td>Data 2</td>' +
                '<td>Data 3</td>' +
              '</tr>' 
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How to select rows where column value IS NOT NULL using CodeIgniter's ActiveRecord?

Codeigniter generates an "IS NULL" query by just leaving the call with no parameters:

$this->db->where('column');

The generated query is:

WHERE `column` IS NULL

newline in <td title="">

This should be OK, but is Internet Explorer specific:

<td title="lineone
linetwo 
etc...">

As others have mentioned, the only other way is to use an HTML + JavaScript based tooltip if you're only interested in the tooltip. If this is for accessibility then you will probably need to stick to just single lines for consistency.

How to locate and insert a value in a text box (input) using Python Selenium?

Assuming your page is available under "http://example.com"

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

driver = webdriver.Firefox()
driver.get("http://example.com")

Select element by id:

inputElement = driver.find_element_by_id("a1")
inputElement.send_keys('1')

Now you can simulate hitting ENTER:

inputElement.send_keys(Keys.ENTER)

or if it is a form you can submit:

inputElement.submit() 

get string from right hand side

I just found out that regexp_substr() is perfect for this purpose :)

My challenge is picking the right-hand 16 chars from a reference string which theoretically can be everything from 7ish to 250ish chars long. It annoys me that substr( OurReference , -16 ) returns null when length( OurReference ) < 16. (On the other hand, it's kind of logical, too, that Oracle consequently returns null whenever a call to substr() goes beyond a string's boundaries.) However, I can set a regular expression to recognise everything between 1 and 16 of any char right before the end of the string:

regexp_substr( OurReference , '.{1,16}$' )

When it comes to performance issues regarding regular expressions, I can't say which of the GREATER() solution and this one performs best. Anyone test this? Generally I've experienced that regular expressions are quite fast if they're written neat and well (as this one).

Good luck! :)

Add swipe to delete UITableViewCell

You can try this:

func tableView(tableView: UITableView!, canEditRowAtIndexPath indexPath: NSIndexPath!) -> Bool {
    return true
}

func tableView(tableView: UITableView!, commitEditingStyle editingStyle:   UITableViewCellEditingStyle, forRowAtIndexPath indexPath: NSIndexPath!) {
    if (editingStyle == UITableViewCellEditingStyle.Delete) {
        NamesTable.beginUpdates()
        Names.removeAtIndex(indexPath!.row)
        NamesTable.deleteRowsAtIndexPaths([indexPath], withRowAnimation: nil)
        NamesTable.endUpdates()

    }
}

where to place CASE WHEN column IS NULL in this query

Thanks for all your help! @Svetoslav Tsolov had it very close, but I was still getting an error, until I figured out the closing parenthesis was in the wrong place. Here's the final query that works:

SELECT dbo.AdminID.CountryID, dbo.AdminID.CountryName, dbo.AdminID.RegionID, 
dbo.AdminID.[Region name], dbo.AdminID.DistrictID, dbo.AdminID.DistrictName,
dbo.AdminID.ADMIN3_ID, dbo.AdminID.ADMIN3,
(CASE WHEN dbo.EU_Admin3.EUID IS NULL THEN dbo.EU_Admin2.EUID ELSE dbo.EU_Admin3.EUID END) AS EUID
FROM dbo.AdminID 

LEFT OUTER JOIN dbo.EU_Admin2
ON dbo.AdminID.DistrictID = dbo.EU_Admin2.DistrictID

LEFT OUTER JOIN dbo.EU_Admin3
ON dbo.AdminID.ADMIN3_ID = dbo.EU_Admin3.ADMIN3_ID

Need help rounding to 2 decimal places

It is caused by a lack of precision with doubles / decimals (i.e. - the function will not always give the result you expect).

See the following link: MSDN on Math.Round

Here is the relevant quote:

Because of the loss of precision that can result from representing decimal values as floating-point numbers or performing arithmetic operations on floating-point values, in some cases the Round(Double, Int32, MidpointRounding) method may not appear to round midpoint values as specified by the mode parameter.This is illustrated in the following example, where 2.135 is rounded to 2.13 instead of 2.14.This occurs because internally the method multiplies value by 10digits, and the multiplication operation in this case suffers from a loss of precision.

Convert a double to a QString

Use QString's number method (docs are here):

double valueAsDouble = 1.2;
QString valueAsString = QString::number(valueAsDouble);

golang why don't we have a set datastructure

Like Vatine wrote: Since go lacks generics it would have to be part of the language and not the standard library. For that you would then have to pollute the language with keywords set, union, intersection, difference, subset...

The other reason is, that it's not clear at all what the "right" implementation of a set is:

  1. There is a functional approach:

    func IsInEvenNumbers(n int) bool {
        if n % 2 == 0 {
            return true
        }
       return false
    }
    

This is a set of all even ints. It has a very efficient lookup and union, intersect, difference and subset can easily be done by functional composition.

  1. Or you do a has-like approach like Dali showed.

A map does not have that problem, since you store something associated with the value.

Uncaught ReferenceError: <function> is not defined at HTMLButtonElement.onclick

Same Problem I had... I was writing all the script in a seperate file and was adding it through tag into the end of the HTML file after body tag. After moving the the tag inside the body tag it works fine. before :

</body>
<script>require('../script/viewLog.js')</script>

after :

<script>require('../script/viewLog.js')</script>
</body>

Need to ZIP an entire directory using Node.js

I ended up wrapping archiver to emulate JSZip, as refactoring through my project woult take too much effort. I understand Archiver might not be the best choice, but here you go.

// USAGE:
const zip=JSZipStream.to(myFileLocation)
    .onDone(()=>{})
    .onError(()=>{});

zip.file('something.txt','My content');
zip.folder('myfolder').file('something-inFolder.txt','My content');
zip.finalize();

// NodeJS file content:
    var fs = require('fs');
    var path = require('path');
    var archiver = require('archiver');

  function zipper(archive, settings) {
    return {
        output: null,
        streamToFile(dir) {
            const output = fs.createWriteStream(dir);
            this.output = output;
            archive.pipe(output);

            return this;
        },
        file(location, content) {
            if (settings.location) {
                location = path.join(settings.location, location);
            }
            archive.append(content, { name: location });
            return this;
        },
        folder(location) {
            if (settings.location) {
                location = path.join(settings.location, location);
            }
            return zipper(archive, { location: location });
        },
        finalize() {
            archive.finalize();
            return this;
        },
        onDone(method) {
            this.output.on('close', method);
            return this;
        },
        onError(method) {
            this.output.on('error', method);
            return this;
        }
    };
}

exports.JSzipStream = {
    to(destination) {
        console.log('stream to',destination)
        const archive = archiver('zip', {
            zlib: { level: 9 } // Sets the compression level.
        });
        return zipper(archive, {}).streamToFile(destination);
    }
};

setTimeout in React Native

On ReactNative .53, the following works for me:

 this.timeoutCheck = setTimeout(() => {
   this.setTimePassed();
   }, 400);

'setTimeout' is the ReactNative library function.
'this.timeoutCheck' is my variable to hold the time out object.
'this.setTimePassed' is my function to invoke at the time out.

How can we stop a running java process through Windows cmd?

FOR /F "tokens=1,2 delims= " %%G IN ('jps -l') DO IF %%H==name.for.the.application.main.Class taskkill /F /PID %%G

name.for.the.application.main.Class - replace this to your application's main class (you can find it in second column of jps -l output)

How to create multiple class objects with a loop in python?

Using a dictionary for unique names without a name list:

class MyClass:
    def __init__(self, name):
        self.name = name
        self.pretty_print_name()

    def pretty_print_name(self):
    print("This object's name is {}.".format(self.name))

my_objects = {}
for i in range(1,11):
    name = 'obj_{}'.format(i)
    my_objects[name] = my_objects.get(name, MyClass(name = name))

Output:

"This object's name is obj_1."
"This object's name is obj_2."
"This object's name is obj_3."
"This object's name is obj_4."
"This object's name is obj_5."
"This object's name is obj_6."
"This object's name is obj_7."
"This object's name is obj_8."
"This object's name is obj_9."
"This object's name is obj_10."

How to read data of an Excel file using C#?

Excel File Reader & Writer Without Excel On u'r System

  • Download and add the dll for NPOI u'r project.
  • Using this code to read a excel file.

            using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
            {
               XSSFWorkbook XSSFWorkbook = new XSSFWorkbook(file);
            }
            ISheet objxlWorkSheet = XSSFWorkbook.GetSheetAt(0);
            int intRowCount = 1;
            int intColumnCount = 0;
            for (; ; )
            {
                IRow Row = objxlWorkSheet.GetRow(intRowCount);
                if (Row != null)
                {
                    ICell Cell = Row.GetCell(0);
                    ICell objCell = objxlWorkSheet.GetRow(intRowCount).GetCell(intColumnCount); }}
    

Mongoose (mongodb) batch insert?

Model.create() vs Model.collection.insert(): a faster approach

Model.create() is a bad way to do inserts if you are dealing with a very large bulk. It will be very slow. In that case you should use Model.collection.insert, which performs much better. Depending on the size of the bulk, Model.create() will even crash! Tried with a million documents, no luck. Using Model.collection.insert it took just a few seconds.

Model.collection.insert(docs, options, callback)
  • docs is the array of documents to be inserted;
  • options is an optional configuration object - see the docs
  • callback(err, docs) will be called after all documents get saved or an error occurs. On success, docs is the array of persisted documents.

As Mongoose's author points out here, this method will bypass any validation procedures and access the Mongo driver directly. It's a trade-off you have to make since you're handling a large amount of data, otherwise you wouldn't be able to insert it to your database at all (remember we're talking hundreds of thousands of documents here).

A simple example

var Potato = mongoose.model('Potato', PotatoSchema);

var potatoBag = [/* a humongous amount of potato objects */];

Potato.collection.insert(potatoBag, onInsert);

function onInsert(err, docs) {
    if (err) {
        // TODO: handle error
    } else {
        console.info('%d potatoes were successfully stored.', docs.length);
    }
}

Update 2019-06-22: although insert() can still be used just fine, it's been deprecated in favor of insertMany(). The parameters are exactly the same, so you can just use it as a drop-in replacement and everything should work just fine (well, the return value is a bit different, but you're probably not using it anyway).

Reference

Typescript : Property does not exist on type 'object'

You probably have allProviders typed as object[] as well. And property country does not exist on object. If you don't care about typing, you can declare both allProviders and countryProviders as Array<any>:

let countryProviders: Array<any>;
let allProviders: Array<any>;

If you do want static type checking. You can create an interface for the structure and use it:

interface Provider {
    region: string,
    country: string,
    locale: string,
    company: string
}

let countryProviders: Array<Provider>;
let allProviders: Array<Provider>;

How to resolve "must be an instance of string, string given" prior to PHP 7?

Prior to PHP 7 type hinting can only be used to force the types of objects and arrays. Scalar types are not type-hintable. In this case an object of the class string is expected, but you're giving it a (scalar) string. The error message may be funny, but it's not supposed to work to begin with. Given the dynamic typing system, this actually makes some sort of perverted sense.

You can only manually "type hint" scalar types:

function foo($string) {
    if (!is_string($string)) {
        trigger_error('No, you fool!');
        return;
    }
    ...
}

Why is &#65279; appearing in my HTML?

yeah, its so simple to fix that, just open that file by notepad++ and step follow --> Encoding\ encoding UTF-8 without BOM. then save that. It work for me as well!

How to use callback with useState hook in react

setState(updater, callback) for useState

Following implementation comes really close to the original setState callback from classes.

Additions made to Robin's solution:

  1. Callback execution is omitted on initial render (we want to call it only on state updates)
  2. Callback can be dynamic for each setState invocation, like with classes

Usage

const App = () => {
  const [state, setState] = useStateCallback(0); // same API as useState + setState with cb

  const handleClick = () => {
    setState(
      prev => prev + 1,
      // 2nd argument is callback , `s` is *updated* state
      s => console.log("I am called after setState, state:", s)
    );
  };

  return <button onClick={handleClick}>Increment</button>;
}

useStateCallback

function useStateCallback(initialState) {
  const [state, setState] = useState(initialState);
  const cbRef = useRef(null); // mutable ref to store current callback

  const setStateCallback = useCallback((state, cb) => {
    cbRef.current = cb; // store passed callback to ref
    setState(state);
  }, []);

  useEffect(() => {
    // cb.current is `null` on initial render, so we only execute cb on state *updates*
    if (cbRef.current) {
      cbRef.current(state);
      cbRef.current = null; // reset callback after execution
    }
  }, [state]);

  return [state, setStateCallback];
}

Further info: React Hooks FAQ: Is there something like instance variables?

Working example

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const App = () => {
  const [state, setState] = useStateCallback(0);

  const handleClick = () =>
    setState(
      prev => prev + 1,
      // important: use `s`, not the stale/old closure value `state`
      s => console.log("I am called after setState, state:", s)
    );

  return (
    <div>
      <p>Hello Comp. State: {state} </p>
      <button onClick={handleClick}>Click me</button>
    </div>
  );
}

function useStateCallback(initialState) {
  const [state, setState] = useState(initialState);
  const cbRef = useRef(null);

  const setStateCallback = useCallback((state, cb) => {
    cbRef.current = cb; 
    setState(state);
  }, []);

  useEffect(() => {
    if (cbRef.current) {
      cbRef.current(state);
      cbRef.current = null;
    }
  }, [state]);

  return [state, setStateCallback];
}

ReactDOM.render(<App />, document.getElementById("root"));
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<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.13.0/umd/react.production.min.js" integrity="sha256-32Gmw5rBDXyMjg/73FgpukoTZdMrxuYW7tj8adbN8z4=" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.13.0/umd/react-dom.production.min.js" integrity="sha256-bjQ42ac3EN0GqK40pC9gGi/YixvKyZ24qMP/9HiGW7w=" crossorigin="anonymous"></script>
<script>var { useReducer, useEffect, useState, useRef, useCallback } = React</script>
<div id="root"></div>
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How do I free memory in C?

You have to free() the allocated memory in exact reverse order of how it was allocated using malloc().

Note that You should free the memory only after you are done with your usage of the allocated pointers.

memory allocation for 1D arrays:

    buffer = malloc(num_items*sizeof(double));

memory deallocation for 1D arrays:

    free(buffer);

memory allocation for 2D arrays:

    double **cross_norm=(double**)malloc(150 * sizeof(double *));
    for(i=0; i<150;i++)
    {
        cross_norm[i]=(double*)malloc(num_items*sizeof(double));
    }

memory deallocation for 2D arrays:

    for(i=0; i<150;i++)
    {
        free(cross_norm[i]);
    }

    free(cross_norm);

Determine a user's timezone

-new Date().getTimezoneOffset()/60;

The method getTimezoneOffset() will subtract your time from GMT and return the number of minutes. So if you live in GMT-8, it will return 480.

To put this into hours, divide by 60. Also, notice that the sign is the opposite of what you need - it's calculating GMT's offset from your time zone, not your time zone's offset from GMT. To fix this, simply multiply by -1.

Also note that w3school says:

The returned value is not a constant, because of the practice of using Daylight Saving Time.

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

I had this on Ubuntu and as I've figured out, there was more than one instance of mysqld.

It looked like the previous one had not been completely stopped, while the new one has already started. Running '/etc/init.d/mysql stop' didn't help, it was always returning 'OK' and a new instance has been launched automatically immediately after that:

        $ sudo /etc/init.d/mysql stop
         * Stopping MySQL database server mysqld        [ OK ] 
        $ pgrep mysql
        28315
        $ sudo /etc/init.d/mysql stop
         * Stopping MySQL database server mysqld        [ OK ] 
        $ pgrep mysql
        28570
        $ sudo /etc/init.d/mysql stop
         * Stopping MySQL database server mysqld        [ OK ] 
        $ pgrep mysql
        28763
        ..... etc ...

Fortunately, the following command has fixed the problem:

    $ sudo service mysql stop
    mysql stop/waiting

    $ ps -ef | grep mysql
    29841 26858  0 10:59 pts/8    00:00:00 grep --color=auto mysql <--- IT's gone ! 

After that I was able to start mysql again and see that mysql.sock has been successfully created.

Ignoring a class property in Entity Framework 4.1 Code First

As of EF 5.0, you need to include the System.ComponentModel.DataAnnotations.Schema namespace.

git push to specific branch

I would like to add an updated answer - now I have been using git for a while, I find that I am often using the following commands to do any pushing (using the original question as the example):

  • git push origin amd_qlp_tester - push to the branch located in the remote called origin on remote-branch called amd_qlp_tester.
  • git push -u origin amd_qlp_tester - same as last one, but sets the upstream linking the local branch to the remote branch so that next time you can just use git push/pull if not already linked (only need to do it once).
  • git push - Once you have set the upstream you can just use this shorter version.

Note -u option is the short version of --set-upstream - they are the same.

How to include CSS file in Symfony 2 and Twig?

You are doing everything right, except passing your bundle path to asset() function.

According to documentation - in your example this should look like below:

{{ asset('bundles/webshome/css/main.css') }}

Tip: you also can call assets:install with --symlink key, so it will create symlinks in web folder. This is extremely useful when you often apply js or css changes (in this way your changes, applied to src/YouBundle/Resources/public will be immediately reflected in web folder without need to call assets:install again):

app/console assets:install web --symlink

Also, if you wish to add some assets in your child template, you could call parent() method for the Twig block. In your case it would be like this:

{% block stylesheets %}
    {{ parent() }}

    <link href="{{ asset('bundles/webshome/css/main.css') }}" rel="stylesheet">
{% endblock %}

PHP display image BLOB from MySQL

Since I have to store various types of content in my blob field/column, I am suppose to update my code like this:

echo "data: $mime" $result['$data']";

where: mime can be an image of any kind, text, word document, text document, PDF document, etc... content datatype is blob in database.

Download File Using jQuery

 var link=document.createElement('a');
 document.body.appendChild(link);
 link.href=url;
 link.click();

Returning multiple objects in an R function

One way to handle this is to put the information as an attribute on the primary one. I must stress, I really think this is the appropriate thing to do only when the two pieces of information are related such that one has information about the other.

For example, I sometimes stash the name of "crucial variables" or variables that have been significantly modified by storing a list of variable names as an attribute on the data frame:

attr(my.DF, 'Modified.Variables') <- DVs.For.Analysis$Names.of.Modified.Vars
return(my.DF)

This allows me to store a list of variable names with the data frame itself.

Identifying country by IP address

I think what you're looking for is an IP Geolocation database or service provider. There are many out there and some are free (get what you pay for).

Although I haven't used this service before, it claims to be in real-time. https://kickfire.com/kf-api

Here's another IP geo location API from Abstract API - https://www.abstractapi.com/ip-geolocation-api

But just do a google search on IP geo and you'll get more results than you need.

java.lang.ClassNotFoundException: org.apache.jsp.index_jsp

I had to delete Tomcat's work directory as it had cached previously generated files. To do this:

  1. Stop Tomcat
  2. Delete the 'work' directory
  3. Start Tomcat

This will cause the work directory to be newly generated.

Illegal Escape Character "\"

The character '\' is a special character and needs to be escaped when used as part of a String, e.g., "\". Here is an example of a string comparison using the '\' character:

if (invName.substring(j,k).equals("\\")) {...}

You can also perform direct character comparisons using logic similar to the following:

if (invName.charAt(j) == '\\') {...}

How can I post an array of string to ASP.NET MVC Controller without a form?

You can setup global parameter with

jQuery.ajaxSettings.traditional = true;

How can I strip all punctuation from a string in JavaScript using regex?

In a Unicode-aware language, the Unicode Punctuation character property is \p{P} — which you can usually abbreviate \pP and sometimes expand to \p{Punctuation} for readability.

Are you using a Perl Compatible Regular Expression library?

Add external libraries to CMakeList.txt c++

I would start with upgrade of CMAKE version.

You can use INCLUDE_DIRECTORIES for header location and LINK_DIRECTORIES + TARGET_LINK_LIBRARIES for libraries

INCLUDE_DIRECTORIES(your/header/dir)
LINK_DIRECTORIES(your/library/dir)
rosbuild_add_executable(kinectueye src/kinect_ueye.cpp)
TARGET_LINK_LIBRARIES(kinectueye lib1 lib2 lib2 ...)

note that lib1 is expanded to liblib1.so (on Linux), so use ln to create appropriate links in case you do not have them

JavaScript - Getting HTML form values

Several easy-to-use form serializers with good documentation.

In order of Github stars,

  1. jquery.serializeJSON

  2. jquery-serialize-object

  3. form2js

  4. form-serialize

Create 3D array using Python

d3 = [[[0 for col in range(4)]for row in range(4)] for x in range(6)]

d3[1][2][1]  = 144

d3[4][3][0]  = 3.12

for x in range(len(d3)):
    print d3[x]



[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]
[[0, 0, 0, 0], [0, 0, 0, 0], [0, 144, 0, 0], [0, 0, 0, 0]]
[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]
[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]
[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [3.12, 0, 0, 0]]
[[0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0]]

How can I sort generic list DESC and ASC?

I was checking all the answer above and wanted to add one more additional information. I wanted to sort the list in DESC order and I was searching for the solution which is faster for bigger inputs and I was using this method earlier :-

li.Sort();
li.Reverse();

but my test cases were failing for exceeding time limits, so below solution worked for me:-

li.Sort((a, b) => b.CompareTo(a));

So Ultimately the conclusion is that 2nd way of Sorting list in Descending order is bit faster than the previous one.

android set button background programmatically

Further from @finnmglas, the Java answer as of 2021 is:

    if (Build.VERSION.SDK_INT >= 29)
        btn.getBackground().setColorFilter(new BlendModeColorFilter(color, BlendMode.MULTIPLY));
    else
        btn.getBackground().setColorFilter(color, PorterDuff.Mode.MULTIPLY);

PDF Blob - Pop up window not showing content

I ended up just downloading my pdf using below code

function downloadPdfDocument(fileName){

var req = new XMLHttpRequest();
req.open("POST", "/pdf/" + fileName, true);
req.responseType = "blob";
fileName += "_" + new Date() + ".pdf";

req.onload = function (event) {

    var blob = req.response;

    //for IE
    if (window.navigator && window.navigator.msSaveOrOpenBlob) {
        window.navigator.msSaveOrOpenBlob(blob, fileName);
    } else {

        var link = document.createElement('a');
        link.href = window.URL.createObjectURL(blob);
        link.download = fileName;
        link.click();
    }
};

req.send();

}

Missing artifact com.oracle:ojdbc6:jar:11.2.0 in pom.xml

You need to check your config file if it has correct values such as systempath and artifact Id.

    <dependency>
    <groupId>com.oracle</groupId>
    <artifactId>ojdbc6</artifactId>
    <version>1.0</version>
    <scope>system</scope>
    <systemPath>C:\Users\Akshay\Downloads\ojdbc6.jar</systemPath>
    </dependency> 

PostgreSQL: ERROR: operator does not exist: integer = character varying

I think it is telling you exactly what is wrong. You cannot compare an integer with a varchar. PostgreSQL is strict and does not do any magic typecasting for you. I'm guessing SQLServer does typecasting automagically (which is a bad thing).

If you want to compare these two different beasts, you will have to cast one to the other using the casting syntax ::.

Something along these lines:

create view view1
as 
select table1.col1,table2.col1,table3.col3
from table1 
inner join
table2 
inner join 
table3
on 
table1.col4::varchar = table2.col5
/* Here col4 of table1 is of "integer" type and col5 of table2 is of type "varchar" */
/* ERROR: operator does not exist: integer = character varying */
....;

Notice the varchar typecasting on the table1.col4.

Also note that typecasting might possibly render your index on that column unusable and has a performance penalty, which is pretty bad. An even better solution would be to see if you can permanently change one of the two column types to match the other one. Literately change your database design.

Or you could create a index on the casted values by using a custom, immutable function which casts the values on the column. But this too may prove suboptimal (but better than live casting).

How to scroll to an element in jQuery?

Check jQuery.ScrollTo, I think that's the behavior that you want, check the demo.

Received an invalid column length from the bcp client for colid 6

I got this error message with a much more recent ssis version (vs 2015 enterprise, i think it's ssis 2016). I will comment here because this is the first reference that comes up when you google this error message. I think it happens mostly with character columns when the source character size is larger than the target character size. I got this message when I was using an ado.net input to ms sql from a teradata database. Funny because the prior oledb writes to ms sql handled all the character conversion perfectly with no coding overrides. The colid number and the a corresponding Destination Input column # you sometimes get with the colid message are worthless. It's not the column when you count down from the top of the mapping or anything like that. If I were microsoft, I'd be embarrased to give an error message that looks like it's pointing at the problem column when it isn't. I found the problem colid by making an educated guess and then changing the input to the mapping to "Ignore" and then rerun and see if the message went away. In my case and in my environment I fixed it by substr( 'ing the Teradata input to the character size of the ms sql declaration for the output column. Check and make sure your input substr propagates through all you data conversions and mappings. In my case it didn't and I had to delete all my Data Conversion's and Mappings and start over again. Again funny that OLEDB just handled it and ADO.net threw the error and had to have all this intervention to make it work. In general you should use OLEDB when your target is MS Sql.

need to add a class to an element

You are missing a closing h2 tag. It should be:

<h2><!-- Content --></h2> 

Going from MM/DD/YYYY to DD-MMM-YYYY in java

Try this

SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy"); // Set your date format
        String currentData = sdf.format(new Date());
        Toast.makeText(getApplicationContext(), ""+currentData,Toast.LENGTH_SHORT ).show();

How to convert current date to epoch timestamp?

enter image description hereI think this answer needs an update and the solution would go better this way.

from datetime import datetime

datetime.strptime("29.08.2011 11:05:02", "%d.%m.%Y %H:%M:%S").strftime("%s")

or you may use datetime object and format the time using %s to convert it into epoch time.

Converting a Pandas GroupBy output from Series to DataFrame

Maybe I misunderstand the question but if you want to convert the groupby back to a dataframe you can use .to_frame(). I wanted to reset the index when I did this so I included that part as well.

example code unrelated to question

df = df['TIME'].groupby(df['Name']).min()
df = df.to_frame()
df = df.reset_index(level=['Name',"TIME"])

Android eclipse DDMS - Can't access data/data/ on phone to pull files

If gives "permission denied" on adb shell -> su...

Some ROMs are running adbd daemon in secure mode (adbd has no root access and su command does not even show permission ask dialog on the device). In this case you will get "permission denied" when you try cmd -> adb shell -> su. The solution I've found is one app from the famous modder Chainfire called Adbd Insecure.

org.springframework.beans.factory.CannotLoadBeanClassException: Cannot find class

I have faced similar problem

So

I just do

1.update Maven Project

2.install maven.

What does Maven do, in theory and in practice? When is it worth to use it?

What it does

Maven is a "build management tool", it is for defining how your .java files get compiled to .class, packaged into .jar (or .war or .ear) files, (pre/post)processed with tools, managing your CLASSPATH, and all others sorts of tasks that are required to build your project. It is similar to Apache Ant or Gradle or Makefiles in C/C++, but it attempts to be completely self-contained in it that you shouldn't need any additional tools or scripts by incorporating other common tasks like downloading & installing necessary libraries etc.

It is also designed around the "build portability" theme, so that you don't get issues as having the same code with the same buildscript working on one computer but not on another one (this is a known issue, we have VMs of Windows 98 machines since we couldn't get some of our Delphi applications compiling anywhere else). Because of this, it is also the best way to work on a project between people who use different IDEs since IDE-generated Ant scripts are hard to import into other IDEs, but all IDEs nowadays understand and support Maven (IntelliJ, Eclipse, and NetBeans). Even if you don't end up liking Maven, it ends up being the point of reference for all other modern builds tools.

Why you should use it

There are three things about Maven that are very nice.

  1. Maven will (after you declare which ones you are using) download all the libraries that you use and the libraries that they use for you automatically. This is very nice, and makes dealing with lots of libraries ridiculously easy. This lets you avoid "dependency hell". It is similar to Apache Ant's Ivy.

  2. It uses "Convention over Configuration" so that by default you don't need to define the tasks you want to do. You don't need to write a "compile", "test", "package", or "clean" step like you would have to do in Ant or a Makefile. Just put the files in the places in which Maven expects them and it should work off of the bat.

  3. Maven also has lots of nice plug-ins that you can install that will handle many routine tasks from generating Java classes from an XSD schema using JAXB to measuring test coverage with Cobertura. Just add them to your pom.xml and they will integrate with everything else you want to do.

The initial learning curve is steep, but (nearly) every professional Java developer uses Maven or wishes they did. You should use Maven on every project although don't be surprised if it takes you a while to get used to it and that sometimes you wish you could just do things manually, since learning something new sometimes hurts. However, once you truly get used to Maven you will find that build management takes almost no time at all.

How to Start

The best place to start is "Maven in 5 Minutes". It will get you start with a project ready for you to code in with all the necessary files and folders set-up (yes, I recommend using the quickstart archetype, at least at first).

After you get started you'll want a better understanding over how the tool is intended to be used. For that "Better Builds with Maven" is the most thorough place to understand the guts of how it works, however, "Maven: The Complete Reference" is more up-to-date. Read the first one for understanding, but then use the second one for reference.

WebForms UnobtrusiveValidationMode requires a ScriptResourceMapping for jquery

The exception indicates a problem with the unobtrusive JavaScript validation mode. This issue is not Sitefinity specific and occurs in any standard ASP.NET applications when the project targets .NET 4.5 framework and the pre-4.5 validation is not enabled in the web.config file.

Open the web.config file and make sure that there is a ValidationSettings:UnobtrusiveValidationMode in the app settings:

<appSettings>
  <add key="ValidationSettings:UnobtrusiveValidationMode" value="None" />
</appSettings>

Git : fatal: Could not read from remote repository. Please make sure you have the correct access rights and the repository exists

change your ssh url by an http url for your remote 'origin', use:

> git remote set-url origin https://github.com/<user_name>/<repo_name>.git

It will ask for your GitHub password on the git push.

Chrome, Javascript, window.open in new tab

You can't directly control this, because it's an option controlled by Internet Explorer users.

Opening pages using Window.open with a different window name will open in a new browser window like a popup, OR open in a new tab, if the user configured the browser to do so.

EDIT:

A more detailed explanation:

1. In modern browsers, window.open will open in a new tab rather than a popup.

2. You can force a browser to use a new window (‘popup’) by specifying options in the 3rd parameter

3. If the window.open call was not part of a user-initiated event, it’ll open in a new window.

4. A “user initiated event” does not have to the same function call – but it must originate in the function invoked by a user click

5. If a user initiated event delegates or defers a function call (in an event listener or delegate not bound to the click event, or by using setTimeout for example), it loses it’s status as “user initiated”

6. Some popup blockers will allow windows opened from user initiated events, but not those opened otherwise.

7. If any popup is blocked, those normally allowed by a blocker (via user initiated events) will sometimes also be blocked. Some examples…

Forcing a window to open in a new browser instance, instead of a new tab:

window.open('page.php', '', 'width=1000');

The following would qualify as a user-initiated event, even though it calls another function:

function o(){
  window.open('page.php');
}
$('button').addEvent('click', o);

The following would not qualify as a user-initiated event, since the setTimeout defers it:

function g(){
  setTimeout(o, 1);
}
function o(){
  window.open('page.php');
}
$('button').addEvent('click', g);

Transpose list of lists

just for fun, valid rectangles and assuming that m[0] exists

>>> m = [[1,2,3],[4,5,6],[7,8,9]]
>>> [[row[i] for row in m] for i in range(len(m[0]))]
[[1, 4, 7], [2, 5, 8], [3, 6, 9]]

Freeze the top row for an html table only (Fixed Table Header Scrolling)

According to Pure CSS Scrollable Table with Fixed Header , I wrote a DEMO to easily fix the header by setting overflow:auto to the tbody.

table thead tr{
    display:block;
}

table th,table td{
    width:100px;//fixed width
}


table  tbody{
  display:block;
  height:200px;
  overflow:auto;//set tbody to auto
}

CreateProcess: No such file or directory

I was getting this error message, because I was using MinGW-w64, and the commands in <install path>\bin all had a weird prefix. I attempted to call executables in the "target alias" directories instead of in <install path>\bin directories, which resulted in even more problems. That's a no-no according to the FAQ. The solution for me, then, was to create symbolic links to all the prefixed commands. I opened an elevated command prompt and used something like mklink gcc.exe x86_64-w64-mingw32-gcc.exe for every executable, and now my build works.

How to validate white spaces/empty spaces? [Angular 2]

To automatically remove all spaces from input field you need to create custom validator.

removeSpaces(c: FormControl) {
  if (c && c.value) {
    let removedSpaces = c.value.split(' ').join('');
    c.value !== removedSpaces && c.setValue(removedSpaces);
  }
  return null;
}

It works with entered and pasted text.

Hide div if screen is smaller than a certain width

Use media queries. Your CSS code would be:

@media screen and (max-width: 1024px) {
    .yourClass {
        display: none !important;
    }
}

Why use @PostConstruct?

  • because when the constructor is called, the bean is not yet initialized - i.e. no dependencies are injected. In the @PostConstruct method the bean is fully initialized and you can use the dependencies.

  • because this is the contract that guarantees that this method will be invoked only once in the bean lifecycle. It may happen (though unlikely) that a bean is instantiated multiple times by the container in its internal working, but it guarantees that @PostConstruct will be invoked only once.

NoClassDefFoundError while trying to run my jar with java.exe -jar...what's wrong?

if you use external libraries in your program and you try to pack all together in a jar file it's not that simple, because of classpath issues etc.

I'd prefer to use OneJar for this issue.

What does character set and collation mean exactly?

A character set is a subset of all written glyphs. A character encoding specifies how those characters are mapped to numeric values. Some character encodings, like UTF-8 and UTF-16, can encode any character in the Universal Character Set. Others, like US-ASCII or ISO-8859-1 can only encode a small subset, since they use 7 and 8 bits per character, respectively. Because many standards specify both a character set and a character encoding, the term "character set" is often substituted freely for "character encoding".

A collation comprises rules that specify how characters can be compared for sorting. Collations rules can be locale-specific: the proper order of two characters varies from language to language.

Choosing a character set and collation comes down to whether your application is internationalized or not. If not, what locale are you targeting?

In order to choose what character set you want to support, you have to consider your application. If you are storing user-supplied input, it might be hard to foresee all the locales in which your software will eventually be used. To support them all, it might be best to support the UCS (Unicode) from the start. However, there is a cost to this; many western European characters will now require two bytes of storage per character instead of one.

Choosing the right collation can help performance if your database uses the collation to create an index, and later uses that index to provide sorted results. However, since collation rules are often locale-specific, that index will be worthless if you need to sort results according to the rules of another locale.

Solr vs. ElasticSearch

I see that a lot of folks here have answered this ElasticSearch vs Solr question in terms of features and functionality but I don't see much discussion here (or elsewhere) regarding how they compare in terms of performance.

That is why I decided to conduct my own investigation. I took an already coded heterogenous data source micro-service that already used Solr for term search. I switched out Solr for ElasticSearch then I ran both versions on AWS with an already coded load test application and captured the performance metrics for subsequent analysis.

Here is what I found. ElasticSearch had 13% higher throughput when it came to indexing documents but Solr was ten times faster. When it came to querying for documents, Solr had five times more throughput and was five times faster than ElasticSearch.

Update Fragment from ViewPager

You can update the fragment in two different ways,

First way

like @Sajmon

You need to implement getItemPosition(Object obj) method.

This method is called when you call

notifyDataSetChanged()

You can find a example in Github and more information in this post.

enter image description here

Second way

My approach to update fragments within the viewpager is to use the setTag() method for any instantiated view in the instantiateItem() method. So when you want to change the data or invalidate the view that you need, you can call the findViewWithTag() method on the ViewPager to retrieve the previously instantiated view and modify/use it as you want without having to delete/create a new view each time you want to update some value.

@Override
public Object instantiateItem(ViewGroup container, int position) {
    Object object = super.instantiateItem(container, position);
    if (object instanceof Fragment) {
        Fragment fragment = (Fragment) object;
        String tag = fragment.getTag();
        mFragmentTags.put(position, tag);
    }
    return object;
}

public Fragment getFragment(int position) {
    Fragment fragment = null;
    String tag = mFragmentTags.get(position);
    if (tag != null) {
        fragment = mFragmentManager.findFragmentByTag(tag);
    }
    return fragment;
}

You can find a example in Github or more information in this post:

enter image description here

Hide/Show components in react native

If you need the component to remain loaded but hidden you can set the opacity to 0. (I needed this for expo camera for instance)

//in constructor    
this.state = {opacity: 100}

/in component
style = {{opacity: this.state.opacity}}

//when you want to hide
this.setState({opacity: 0})

convert month from name to number

$nmonth = date("m", strtotime($month));

How to execute a .sql script from bash

If you want to run a script to a database:

mysql -u user -p data_base_name_here < db.sql

PowerShell Connect to FTP server and get files

Invoke-WebRequest can download HTTP, HTTPS, and FTP links.

$source = 'ftp://Blah.com/somefile.txt'
$target = 'C:\Users\someuser\Desktop\BlahFiles\somefile.txt'
$password = Microsoft.PowerShell.Security\ConvertTo-SecureString -String 'mypassword' -AsPlainText -Force
$credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList myuserid, $password

# Download
Invoke-WebRequest -Uri $source -OutFile $target -Credential $credential -UseBasicParsing

Since the cmdlet uses IE parsing you may need the -UseBasicParsing switch. Test to make sure.