Name [jdbc/mydb] is not bound in this Context
You need a ResourceLink in your META-INF/context.xml file to make the global resource available to the web application.
<ResourceLink name="jdbc/mydb"
global="jdbc/mydb"
type="javax.sql.DataSource" />
"Invalid form control" only in Google Chrome
Chrome wants to focus on a control that is required but still empty so that it can pop up the message 'Please fill out this field'. However, if the control is hidden at the point that Chrome wants to pop up the message, that is at the time of form submission, Chrome can't focus on the control because it is hidden, therefore the form won't submit.
So, to get around the problem, when a control is hidden by javascript, we also must remove the 'required' attribute from that control.
detect key press in python?
For those who are on windows and were struggling to find an working answer here's mine: pynput
from pynput.keyboard import Key, Listener
def on_press(key):
print('{0} pressed'.format(
key))
def on_release(key):
print('{0} release'.format(
key))
if key == Key.esc:
# Stop listener
return False
# Collect events until released
with Listener(
on_press=on_press,
on_release=on_release) as listener:
listener.join()
The function above will print whichever key you are pressing plus start an action as you release the 'esc' key. The keyboard documentation is here for a more variated usage.
Markus von Broady highlighted a potential issue that is: This answer doesn't require you being in the current window to this script be activated, a solution to windows would be:
from win32gui import GetWindowText, GetForegroundWindow
current_window = (GetWindowText(GetForegroundWindow()))
desired_window_name = "Stopwatch" #Whatever the name of your window should be
#Infinite loops are dangerous.
while True: #Don't rely on this line of code too much and make sure to adapt this to your project.
if current_window == desired_window_name:
with Listener(
on_press=on_press,
on_release=on_release) as listener:
listener.join()
How to compare arrays in JavaScript?
var er = [{id:"23",name:"23222"}, {id:"222",name:"23222222"}];
var er2 = [{id:"23",name:"23222"}, {id:"222",name:"23222222"}];
var result = (JSON.stringify(er) == JSON.stringify(er2)); // true
It works json objects well if the order of the property of each entry is not changed.
var er = [{name:"23222",id:"23"}, {id:"222",name:"23222222"}];
var er2 = [{id:"23",name:"23222"}, {id:"222",name:"23222222"}];
var result = (JSON.stringify(er) == JSON.stringify(er2)); // false
But there is only one property or value in each entry of the array, this will work fine.
subquery in codeigniter active record
I think this code will work. I dont know if this is acceptable query style in CI but it works perfectly in my previous problem. :)
$subquery = 'SELECT id_cer FROM revokace';
$this->db->select('*');
$this->db->where_not_in(id, $subquery);
$this->db->from('certs');
$query = $this->db->get();
How can I convert an Integer to localized month name in Java?
Using SimpleDateFormat.
import java.text.SimpleDateFormat;
public String formatMonth(String month) {
SimpleDateFormat monthParse = new SimpleDateFormat("MM");
SimpleDateFormat monthDisplay = new SimpleDateFormat("MMMM");
return monthDisplay.format(monthParse.parse(month));
}
formatMonth("2");
Result: February
Pandas left outer join multiple dataframes on multiple columns
Merge them in two steps, df1 and df2 first, and then the result of that to df3.
In [33]: s1 = pd.merge(df1, df2, how='left', on=['Year', 'Week', 'Colour'])
I dropped year from df3 since you don't need it for the last join.
In [39]: df = pd.merge(s1, df3[['Week', 'Colour', 'Val3']],
how='left', on=['Week', 'Colour'])
In [40]: df
Out[40]:
Year Week Colour Val1 Val2 Val3
0 2014 A Red 50 NaN NaN
1 2014 B Red 60 NaN 60
2 2014 B Black 70 100 10
3 2014 C Red 10 20 NaN
4 2014 D Green 20 NaN 20
[5 rows x 6 columns]
How to change background color in the Notepad++ text editor?
You may need admin access to do it on your system.
- Create a folder 'themes' in the Notepad++ installation folder i.e.
C:\Program Files (x86)\Notepad++
- Search or visit pages like http://timtrott.co.uk/notepad-colour-schemes/ to download the favourite theme. It will be an SML file.
- Note: I prefer Neon any day.
- Download the themes from the site and drag them to the
themes folder.
- Note: I was unable to copy-paste or create new files in 'themes' folder so I used drag and that worked.
- Follow the steps provided by @triforceofcourage to select the new theme in Notepad++ preferences.
Javascript window.open pass values using POST
thanks php-b-grader !
below the generic function for window.open pass values using POST:
function windowOpenInPost(actionUrl,windowName, windowFeatures, keyParams, valueParams)
{
var mapForm = document.createElement("form");
var milliseconds = new Date().getTime();
windowName = windowName+milliseconds;
mapForm.target = windowName;
mapForm.method = "POST";
mapForm.action = actionUrl;
if (keyParams && valueParams && (keyParams.length == valueParams.length)){
for (var i = 0; i < keyParams.length; i++){
var mapInput = document.createElement("input");
mapInput.type = "hidden";
mapInput.name = keyParams[i];
mapInput.value = valueParams[i];
mapForm.appendChild(mapInput);
}
document.body.appendChild(mapForm);
}
map = window.open('', windowName, windowFeatures);
if (map) {
mapForm.submit();
} else {
alert('You must allow popups for this map to work.');
}}
How do I install a Python package with a .whl file?
To be able to install wheel files with a simple doubleclick on them you can do one the following:
1) Run two commands in command line under administrator privileges:
assoc .whl=pythonwheel
ftype pythonwheel=cmd /c pip.exe install "%1" ^& pause
2) Alternatively, they can be copied into a wheel.bat file and executed with 'Run as administrator' checkbox in the properties.
PS pip.exe is assumed to be in the PATH.
Update:
(1) Those can be combined in one line:
assoc .whl=pythonwheel& ftype pythonwheel=cmd /c pip.exe install -U "%1" ^& pause
(2) Syntax for .bat files is slightly different:
assoc .whl=pythonwheel& ftype pythonwheel=cmd /c pip.exe install -U "%%1" ^& pause
Also its output can be made more verbose:
@assoc .whl=pythonwheel|| echo Run me with administrator rights! && pause && exit 1
@ftype pythonwheel=cmd /c pip.exe install -U "%%1" ^& pause || echo Installation error && pause && exit 1
@echo Installation successfull & pause
see my blog post for details.
react-router (v4) how to go back?
You can use history.goBack() in functional component. Just like this.
import { useHistory } from 'react-router';
const component = () => {
const history = useHistory();
return (
<button onClick={() => history.goBack()}>Previous</button>
)
}
jQuery scroll to ID from different page
function scroll_down(){
$.noConflict();
jQuery(document).ready(function($) {
$('html, body').animate({
scrollTop : $("#bottom").offset().top
}, 1);
});
return false;
}
here "bottom" is the div tag id where you want to scroll to. For changing the animation effects, you can change the time from '1' to a different value
How to fix curl: (60) SSL certificate: Invalid certificate chain
After updating to OS X 10.9.2, I started having invalid SSL certificate issues with Homebrew, Textmate, RVM, and Github.
When I initiate a brew update, I was getting the following error:
fatal: unable to access 'https://github.com/Homebrew/homebrew/': SSL certificate problem: Invalid certificate chain
Error: Failure while executing: git pull -q origin refs/heads/master:refs/remotes/origin/master
I was able to alleviate some of the issue by just disabling the SSL verification in Git. From the console (a.k.a. shell or terminal):
git config --global http.sslVerify false
I am leary to recommend this because it defeats the purpose of SSL, but it is the only advice I've found that works in a pinch.
I tried rvm osx-ssl-certs update all which stated Already are up to date.
In Safari, I visited https://github.com and attempted to set the certificate manually, but Safari did not present the options to trust the certificate.
Ultimately, I had to Reset Safari (Safari->Reset Safari... menu). Then afterward visit github.com and select the certificate, and "Always trust" This feels wrong and deletes the history and stored passwords, but it resolved my SSL verification issues. A bittersweet victory.
Install Qt on Ubuntu
In Ubuntu 18.04 the QtCreator examples and API docs missing,
This is my way to solve this problem, should apply to almost every Ubuntu release.
For QtCreator and Examples and API Docs:
sudo apt install `apt-cache search 5-examples | grep qt | grep example | awk '{print $1 }' | xargs `
sudo apt install `apt-cache search 5-doc | grep "Qt 5 " | awk '{print $1}' | xargs`
sudo apt-get install build-essential qtcreator qt5-default
If something is also missing, then:
sudo apt install `apt-cache search qt | grep 5- | grep ^qt | awk '{print $1}' | xargs `
Hope to be helpful.
Also posted in Ask Ubuntu: https://askubuntu.com/questions/450983/ubuntu-14-04-qtcreator-qt5-examples-missing
mysqli_fetch_assoc() expects parameter 1 to be mysqli_result, boolean given
Mysqli makes use of object oriented programming. Try using this approach instead:
function dbCon() {
if($mysqli = new mysqli('$hostname','$username','$password','$databasename')) return $mysqli; else return false;
}
if(!dbCon())
exit("<script language='javascript'>alert('Unable to connect to database')</script>");
else $con=dbCon();
if (isset($_GET['part'])){
$partid = $_GET['part'];
$sql = "SELECT *
FROM $usertable
WHERE PartNumber = $partid";
$result=$con->query($sql_query);
$row = $result->fetch_assoc();
$partnumber = $partid;
$nsn = $row["NSN"];
$description = $row["Description"];
$quantity = $row["Quantity"];
$condition = $row["Conditio"];
}
Let me know if you have any questions, I could not test this code so you might need to tripple check it!
Stopping fixed position scrolling at a certain point?
Here's a quick jQuery plugin I just wrote that can do what you require:
$.fn.followTo = function (pos) {
var $this = this,
$window = $(window);
$window.scroll(function (e) {
if ($window.scrollTop() > pos) {
$this.css({
position: 'absolute',
top: pos
});
} else {
$this.css({
position: 'fixed',
top: 0
});
}
});
};
$('#yourDiv').followTo(250);
See working example →
Rails 3.1 and Image Assets
when referencing images in CSS or in an IMG tag, use image-name.jpg
while the image is really located under ./assets/images/image-name.jpg
How to get a json string from url?
If you're using .NET 4.5 and want to use async then you can use HttpClient in System.Net.Http:
using (var httpClient = new HttpClient())
{
var json = await httpClient.GetStringAsync("url");
// Now parse with JSON.Net
}
Javascript change font color
Html code
<div id="coloredBy">
Colored By Santa
</div>
javascript code
document.getElementById("coloredBy").style.color = colorCode; // red or #ffffff
I think this is very easy to use
How do I extract data from JSON with PHP?
You can use json_decode() to convert a json string to a PHP object/array.
Eg.
Input:
$json = '{"a":1,"b":2,"c":3,"d":4,"e":5}';
var_dump(json_decode($json));
var_dump(json_decode($json, true));
Output:
object(stdClass)#1 (5) {
["a"] => int(1)
["b"] => int(2)
["c"] => int(3)
["d"] => int(4)
["e"] => int(5)
}
array(5) {
["a"] => int(1)
["b"] => int(2)
["c"] => int(3)
["d"] => int(4)
["e"] => int(5)
}
Few Points to remember:
json_decode requires the string to be a valid json else it will return NULL.- In the event of a failure to decode,
json_last_error() can be used to determine the exact nature of the error.
- Make sure you pass in
utf8 content, or json_decode may error out and just return a NULL value.
Fetch: reject promise and catch the error if status is not OK?
Fetch promises only reject with a TypeError when a network error occurs. Since 4xx and 5xx responses aren't network errors, there's nothing to catch. You'll need to throw an error yourself to use Promise#catch.
A fetch Response conveniently supplies an ok , which tells you whether the request succeeded. Something like this should do the trick:
fetch(url).then((response) => {
if (response.ok) {
return response.json();
} else {
throw new Error('Something went wrong');
}
})
.then((responseJson) => {
// Do something with the response
})
.catch((error) => {
console.log(error)
});
Copy-item Files in Folders and subfolders in the same directory structure of source server using PowerShell
one time i found this script, this copy folder and files and keep the same structure of the source in the destination, you can make some tries with this.
# Find the source files
$sourceDir="X:\sourceFolder"
# Set the target file
$targetDir="Y:\Destfolder\"
Get-ChildItem $sourceDir -Include *.* -Recurse | foreach {
# Remove the original root folder
$split = $_.Fullname -split '\\'
$DestFile = $split[1..($split.Length - 1)] -join '\'
# Build the new destination file path
$DestFile = $targetDir+$DestFile
# Move-Item won't create the folder structure so we have to
# create a blank file and then overwrite it
$null = New-Item -Path $DestFile -Type File -Force
Move-Item -Path $_.FullName -Destination $DestFile -Force
}
How to use Java property files?
In Java 8 to get all your properties
public static Map<String, String> readPropertiesFile(String location) throws Exception {
Map<String, String> properties = new HashMap<>();
Properties props = new Properties();
props.load(new FileInputStream(new File(location)));
props.forEach((key, value) -> {
properties.put(key.toString(), value.toString());
});
return properties;
}
Java Multithreading concept and join() method
No words just running code
// Thread class
public class MyThread extends Thread {
String result = null;
public MyThread(String name) {
super(name);
}
public void run() {
for (int i = 0; i < 1000; i++) {
System.out.println("Hello from " + this.getName());
}
result = "Bye from " + this.getName();
}
}
Main Class
public class JoinRND {
public static void main(String[] args) {
System.out.println("Show time");
// Creating threads
MyThread m1 = new MyThread("Thread M1");
MyThread m2 = new MyThread("Thread M2");
MyThread m3 = new MyThread("Thread M3");
// Starting out Threads
m1.start();
m2.start();
m3.start();
// Just checking current value of thread class variable
System.out.println("M1 before: " + m1.result);
System.out.println("M2 before: " + m2.result);
System.out.println("M3 before: " + m3.result);
// After starting all threads main is performing its own logic in
// parallel to other threads
for (int i = 0; i < 1000; i++) {
System.out.println("Hello from Main");
}
try {
System.out
.println("Main is waiting for other threads to get there task completed");
m1.join();
m2.join();
m3.join();
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("M1 after" + m1.result);
System.out.println("M2 after" + m2.result);
System.out.println("M3 after" + m3.result);
System.out.println("Show over");
}
}
Converting char[] to byte[]
You could make a method:
public byte[] toBytes(char[] data) {
byte[] toRet = new byte[data.length];
for(int i = 0; i < toRet.length; i++) {
toRet[i] = (byte) data[i];
}
return toRet;
}
Hope this helps
MySQL - UPDATE query based on SELECT Query
I found this question in looking for my own solution to a very complex join. This is an alternative solution, to a more complex version of the problem, which I thought might be useful.
I needed to populate the product_id field in the activities table, where activities are numbered in a unit, and units are numbered in a level (identified using a string ??N), such that one can identify activities using an SKU ie L1U1A1. Those SKUs are then stored in a different table.
I identified the following to get a list of activity_id vs product_id:-
SELECT a.activity_id, w.product_id
FROM activities a
JOIN units USING(unit_id)
JOIN product_types USING(product_type_id)
JOIN web_products w
ON sku=CONCAT('L',SUBSTR(product_type_code,3), 'U',unit_index, 'A',activity_index)
I found that that was too complex to incorporate into a SELECT within mysql, so I created a temporary table, and joined that with the update statement:-
CREATE TEMPORARY TABLE activity_product_ids AS (<the above select statement>);
UPDATE activities a
JOIN activity_product_ids b
ON a.activity_id=b.activity_id
SET a.product_id=b.product_id;
I hope someone finds this useful
Sorting table rows according to table header column using javascript or jquery
You might want to see this page:
http://blog.niklasottosson.com/?p=1914
I guess you can go something like this:
DEMO:http://jsfiddle.net/g9eL6768/2/
HTML:
<table id="mytable"><thead>
<tr>
<th id="sl">S.L.</th>
<th id="nm">name</th>
</tr>
....
JS:
// sortTable(f,n)
// f : 1 ascending order, -1 descending order
// n : n-th child(<td>) of <tr>
function sortTable(f,n){
var rows = $('#mytable tbody tr').get();
rows.sort(function(a, b) {
var A = getVal(a);
var B = getVal(b);
if(A < B) {
return -1*f;
}
if(A > B) {
return 1*f;
}
return 0;
});
function getVal(elm){
var v = $(elm).children('td').eq(n).text().toUpperCase();
if($.isNumeric(v)){
v = parseInt(v,10);
}
return v;
}
$.each(rows, function(index, row) {
$('#mytable').children('tbody').append(row);
});
}
var f_sl = 1; // flag to toggle the sorting order
var f_nm = 1; // flag to toggle the sorting order
$("#sl").click(function(){
f_sl *= -1; // toggle the sorting order
var n = $(this).prevAll().length;
sortTable(f_sl,n);
});
$("#nm").click(function(){
f_nm *= -1; // toggle the sorting order
var n = $(this).prevAll().length;
sortTable(f_nm,n);
});
Hope this helps.
Xcode 4: How do you view the console?
There's two options:
Log Navigator (command-7 or view|navigators|log) and select your debug session.
"View | Show Debug Area" to view the NSLog output and interact with the debugger.
Here's a pic with both on. You wouldn't normally have both on, but I can only link one image per post! http://i.stack.imgur.com/4gG4P.png
Authentication versus Authorization
Definitions
Authentication - Are you the person you claim to be?
Authorization - Are you authorized to do whatever it is you're trying to do?
Example
A web app uses Google Sign-In. After a user successfully signs in, Google sends back:
- A JWT token. This can be validated and decoded to get authentication information. Is the token signed by Google? What is the user's name and email?
- An access token. This authorizes the web app to access Google APIs on behalf of the user. For example, can the app access the user's Google Calendar events? These permissions depend on the scopes that were requested, and whether or not the user allowed it.
Additionally:
The company may have an admin dashboard that allows customer support to manage the company's users. Instead of providing a custom signup solution that would allow customer support to access this dashboard, the company uses Google Sign-In.
The JWT token (received from the Google sign in process) is sent to the company's authorization server to figure out if the user has a G Suite account with the organization's hosted domain ([email protected])? And if they do, are they a member of the company's Google Group that was created for customer support? If yes to all of the above, we can consider them authenticated.
The company's authorization server then sends the dashboard app an access token. This access token can be used to make authorized requests to the company's resource server (e.g. ability to make a GET request to an endpoint that sends back all of the company's users).
Is " " a replacement of " "?
is the character entity reference (meant to be easily parseable by humans).  is the numeric entity reference (meant to be easily parseable by machines).
They are the same except for the fact that the latter does not need another lookup table to find its actual value. The lookup table is called a DTD, by the way.
You can read more about character entity references in the offical W3C documents.
Python wildcard search in string
Do you mean any specific syntax for wildcards? Usually * stands for "one or many" characters and ? stands for one.
The simplest way probably is to translate a wildcard expression into a regular expression, then use that for filtering the results.
URL encode sees “&” (ampersand) as “&” HTML entity
Without seeing your code, it's hard to answer other than a stab in the dark. I would guess that the string you're passing to encodeURIComponent(), which is the correct method to use, is coming from the result of accessing the innerHTML property. The solution is to get the innerText/textContent property value instead:
var str,
el = document.getElementById("myUrl");
if ("textContent" in el)
str = encodeURIComponent(el.textContent);
else
str = encodeURIComponent(el.innerText);
If that isn't the case, you can use the replace() method to replace the HTML entity:
encodeURIComponent(str.replace(/&/g, "&"));
android button selector
Create custom_selector.xml in drawable folder
<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
<item android:drawable="@drawable/unselected" android:state_pressed="true" />
<item android:drawable="@drawable/selected" />
</selector>
Create selected.xml shape in drawable folder
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" android:padding="90dp">
<solid android:color="@color/selected"/>
<padding />
<stroke android:color="#000" android:width="1dp"/>
<corners android:bottomRightRadius="15dp" android:bottomLeftRadius="15dp" android:topLeftRadius="15dp" android:topRightRadius="15dp"/>
</shape>
Create unselected.xml shape in drawable folder
<shape xmlns:android="http://schemas.android.com/apk/res/android" android:shape="rectangle" android:padding="90dp">
<solid android:color="@color/unselected"/>
<padding />
<stroke android:color="#000" android:width="1dp"/>
<corners android:bottomRightRadius="15dp" android:bottomLeftRadius="15dp" android:topLeftRadius="15dp" android:topRightRadius="15dp"/>
</shape>
Add following colors for selected/unselected state in color.xml of values folder
<color name="selected">#a8cf45</color>
<color name="unselected">#ff8cae3b</color>
you can check complete solution from here
Changing an element's ID with jQuery
<script>
$(document).ready(function () {
$('select').attr("id", "newId"); //direct descendant of a
});
</script>
This could do for all purpose. Just add before your body closing tag and don't for get to add Jquery.min.js
How to add include path in Qt Creator?
If you are using qmake, the standard Qt build system, just add a line to the .pro file as documented in the qmake Variable Reference:
INCLUDEPATH += <your path>
If you are using your own build system, you create a project by selecting "Import of Makefile-based project". This will create some files in your project directory including a file named <your project name>.includes. In that file, simply list the paths you want to include, one per line. Really all this does is tell Qt Creator where to look for files to index for auto completion. Your own build system will have to handle the include paths in its own way.
As explained in the Qt Creator Manual, <your path> must be an absolute path, but you can avoid OS-, host- or user-specific entries in your .pro file by using $$PWD which refers to the folder that contains your .pro file, e.g.
INCLUDEPATH += $$PWD/code/include
How to set level logging to DEBUG in Tomcat?
Firstly, the level name to use is FINE, not DEBUG. Let's assume for a minute that DEBUG is actually valid, as it makes the following explanation make a bit more sense...
In the Handler specific properties section, you're setting the logging level for those handlers to DEBUG. This means the handlers will handle any log messages with the DEBUG level or higher. It doesn't necessarily mean any DEBUG messages are actually getting passed to the handlers.
In the Facility specific properties section, you're setting the logging level for a few explicitly-named loggers to DEBUG. For those loggers, anything at level DEBUG or above will get passed to the handlers.
The default logging level is INFO, and apart from the loggers mentioned in the Facility specific properties section, all loggers will have that level.
If you want to see all FINE messages, add this:
.level = FINE
However, this will generate a vast quantity of log messages. It's probably more useful to set the logging level for your code:
your.package.level = FINE
See the Tomcat 6/Tomcat 7 logging documentation for more information. The example logging.properties file shown there uses FINE instead of DEBUG:
...
1catalina.org.apache.juli.FileHandler.level = FINE
...
and also gives you examples of setting additional logging levels:
# For example, set the com.xyz.foo logger to only log SEVERE
# messages:
#org.apache.catalina.startup.ContextConfig.level = FINE
#org.apache.catalina.startup.HostConfig.level = FINE
#org.apache.catalina.session.ManagerBase.level = FINE
How does "304 Not Modified" work exactly?
Last-Modified : The last modified date for the requested object
If-Modified-Since : Allows a 304 Not Modified to be returned if last
modified date is unchanged.
ETag : An ETag is an opaque identifier assigned by a web server to a
specific version of a resource found at a URL. If the resource
representation at that URL ever changes, a new and different ETag is
assigned.
If-None-Match : Allows a 304 Not Modified to be returned if ETag is
unchanged.
the browser store cache with a date(Last-Modified) or id(ETag), when you need to request the URL again, the browser send request message with the header:
the server will return 304 when the if statement is False, and browser will use cache.
How can I use xargs to copy files that have spaces and quotes in their names?
Be aware that most of the options discussed in other answers are not standard on platforms that do not use the GNU utilities (Solaris, AIX, HP-UX, for instance). See the POSIX specification for 'standard' xargs behaviour.
I also find the behaviour of xargs whereby it runs the command at least once, even with no input, to be a nuisance.
I wrote my own private version of xargs (xargl) to deal with the problems of spaces in names (only newlines separate - though the 'find ... -print0' and 'xargs -0' combination is pretty neat given that file names cannot contain ASCII NUL '\0' characters. My xargl isn't as complete as it would need to be to be worth publishing - especially since GNU has facilities that are at least as good.
What does it mean when Statement.executeUpdate() returns -1?
As the statement executed is not actually DML (eg UPDATE, INSERT or EXECUTE), but a piece of T-SQL which contains DML, I suspect it is not treated as an update-query.
Section 13.1.2.3 of the JDBC 4.1 specification states something (rather hard to interpret btw):
When the method execute returns true, the method getResultSet is called to
retrieve the ResultSet object. When execute returns false, the method
getUpdateCount returns an int. If this number is greater than or equal to zero, it
indicates the update count returned by the statement. If it is -1, it indicates that there
are no more results.
Given this information, I guess that executeUpdate() internally does an execute(), and then - as execute() will return false - it will return the value of getUpdateCount(), which in this case - in accordance with the JDBC spec - will return -1.
This is further corroborated by the fact 1) that the Javadoc for Statement.executeUpdate() says:
Returns: either (1) the row count for SQL Data Manipulation Language (DML) statements or (2) 0 for SQL statements that return nothing
And 2) that the Javadoc for Statement.getUpdateCount() specifies:
the current result as an update count; -1 if the current result is a ResultSet object or there are no more results
Just to clarify: given the Javadoc for executeUpdate() the behavior is probably wrong, but it can be explained.
Also as I commented elsewhere, the -1 might just indicate: maybe something was changed, but we simply don't know, or we can't give an accurate number of changes (eg because in this example it is a piece of T-SQL that is executed).
What's the best way to store a group of constants that my program uses?
Another vote for using web.config or app.config. The config files are a good place for constants like connection strings, etc. I prefer not to have to look at the source to view or modify these types of things. A static class which reads these constants from a .config file might be a good compromise, as it will let your application access these resources as though they were defined in code, but still give you the flexibility of having them in an easily viewable/editable space.
Execute php file from another php
This came across while working on a project on linux platform.
exec('wget http://<url to the php script>)
This runs as if you run the script from browser.
Hope this helps!!
Laravel-5 'LIKE' equivalent (Eloquent)
I have scopes for this, hope it help somebody.
https://laravel.com/docs/master/eloquent#local-scopes
public function scopeWhereLike($query, $column, $value)
{
return $query->where($column, 'like', '%'.$value.'%');
}
public function scopeOrWhereLike($query, $column, $value)
{
return $query->orWhere($column, 'like', '%'.$value.'%');
}
Usage:
$result = BookingDates::whereLike('email', $email)->orWhereLike('name', $name)->get();
Change Text Color of Selected Option in a Select Box
Try this:
_x000D_
_x000D_
.greenText{ background-color:green; }_x000D_
_x000D_
.blueText{ background-color:blue; }_x000D_
_x000D_
.redText{ background-color:red; }
_x000D_
<select_x000D_
onchange="this.className=this.options[this.selectedIndex].className"_x000D_
class="greenText">_x000D_
<option class="greenText" value="apple" >Apple</option>_x000D_
<option class="redText" value="banana" >Banana</option>_x000D_
<option class="blueText" value="grape" >Grape</option>_x000D_
</select>
_x000D_
_x000D_
_x000D_
What is the best way to seed a database in Rails?
factory_bot sounds like it will do what you are trying to achieve. You can define all the common attributes in the default definition and then override them at creation time. You can also pass an id to the factory:
Factory.define :theme do |t|
t.background_color '0x000000'
t.title_text_color '0x000000',
t.component_theme_color '0x000000'
t.carrier_select_color '0x000000'
t.label_text_color '0x000000',
t.join_upper_gradient '0x000000'
t.join_lower_gradient '0x000000'
t.join_text_color '0x000000',
t.cancel_link_color '0x000000'
t.border_color '0x000000'
t.carrier_text_color '0x000000'
t.public true
end
Factory(:theme, :id => 1, :name => "Lite", :background_color => '0xC7FFD5')
Factory(:theme, :id => 2, :name => "Metallic", :background_color => '0xC7FFD5')
Factory(:theme, :id => 3, :name => "Blues", :background_color => '0x0060EC')
When used with faker it can populate a database really quickly with associations without having to mess about with Fixtures (yuck).
I have code like this in a rake task.
100.times do
Factory(:company, :address => Factory(:address), :employees => [Factory(:employee)])
end
How to get substring in C
char originalString[] = "THESTRINGHASNOSPACES";
char aux[5];
int j=0;
for(int i=0;i<strlen(originalString);i++){
aux[j] = originalString[i];
if(j==3){
aux[j+1]='\0';
printf("%s\n",aux);
j=0;
}else{
j++;
}
}
$.ajax - dataType
(ps: the answer given by Nick Craver is incorrect)
contentType specifies the format of data being sent to the server as part of request(it can be sent as part of response too, more on that later).
dataType specifies the expected format of data to be received by the client(browser).
Both are not interchangable.
contentType is the header sent to the server, specifying the format of data(i.e the content of message body) being being to the server. This is used with POST and PUT requests. Usually when u send POST request, the message body comprises of passed in parameters like:
==============================
Sample request:
POST /search HTTP/1.1
Content-Type: application/x-www-form-urlencoded
<<other header>>
name=sam&age=35
==============================
The last line above "name=sam&age=35" is the message body and contentType specifies it as application/x-www-form-urlencoded since we are passing the form parameters in the message body.
However we aren't limited to just sending the parameters, we can send json, xml,... like this(sending different types of data is especially useful with RESTful web services):
==============================
Sample request:
POST /orders HTTP/1.1
Content-Type: application/xml
<<other header>>
<order>
<total>$199.02</total>
<date>December 22, 2008 06:56</date>
...
</order>
==============================
So the ContentType this time is: application/xml, cause that's what we are sending.
The above examples showed sample request, similarly the response send from the server can also have the Content-Type header specifying what the server is sending like this:
==============================
sample response:
HTTP/1.1 201 Created
Content-Type: application/xml
<<other headers>>
<order id="233">
<link rel="self" href="http://example.com/orders/133"/>
<total>$199.02</total>
<date>December 22, 2008 06:56</date>
...
</order>
==============================
dataType specifies the format of response to expect. Its related to Accept header. JQuery will try to infer it based on the Content-Type of the response.
==============================
Sample request:
GET /someFolder/index.html HTTP/1.1
Host: mysite.org
Accept: application/xml
<<other headers>>
==============================
Above request is expecting XML from the server.
Regarding your question,
contentType: "application/json; charset=utf-8",
dataType: "json",
Here you are sending json data using UTF8 character set, and you expect back json data from the server. As per the JQuery docs for dataType,
The json type parses the fetched data file as a JavaScript object and
returns the constructed object as the result data.
So what you get in success handler is proper javascript object(JQuery converts the json object for you)
whereas
contentType: "application/json",
dataType: "text",
Here you are sending json data, since you haven't mentioned the encoding, as per the JQuery docs,
If no charset is specified, data will be transmitted to the server
using the server's default charset; you must decode this appropriately
on the server side.
and since dataType is specified as text, what you get in success handler is plain text, as per the docs for dataType,
The text and xml types return the data with no processing. The data is
simply passed on to the success handler
How to edit an Android app?
First you have to download file x-plore and installed it..
After that open it and find the thoes you want to edit..
After that just rename the file
Xyz.apk to xyz.zip
After that open that file and you can see some folders.. then just go and edit the app..
Converting datetime.date to UTC timestamp in Python
the question is a little confused. timestamps are not UTC - they're a Unix thing. the date might be UTC? assuming it is, and if you're using Python 3.2+, simple-date makes this trivial:
>>> SimpleDate(date(2011,1,1), tz='utc').timestamp
1293840000.0
if you actually have the year, month and day you don't need to create the date:
>>> SimpleDate(2011,1,1, tz='utc').timestamp
1293840000.0
and if the date is in some other timezone (this matters because we're assuming midnight without an associated time):
>>> SimpleDate(date(2011,1,1), tz='America/New_York').timestamp
1293858000.0
[the idea behind simple-date is to collect all python's date and time stuff in one consistent class, so you can do any conversion. so, for example, it will also go the other way:
>>> SimpleDate(1293858000, tz='utc').date
datetime.date(2011, 1, 1)
]
C error: Expected expression before int
By C89, variable can only be defined at the top of a block.
if (a == 1)
int b = 10; // it's just a statement, syntacitially error
if (a == 1)
{ // refer to the beginning of a local block
int b = 10; // at the top of the local block, syntacitially correct
} // refer to the end of a local block
if (a == 1)
{
func();
int b = 10; // not at the top of the local block, syntacitially error, I guess
}
Scala: join an iterable of strings
How about mkString ?
theStrings.mkString(",")
A variant exists in which you can specify a prefix and suffix too.
See here for an implementation using foldLeft, which is much more verbose, but perhaps worth looking at for education's sake.
Find MongoDB records where array field is not empty
Retrieve all and only the documents where 'pictures' is an array and is not empty
ME.find({pictures: {$type: 'array', $ne: []}})
If using a MongoDb version prior to 3.2, use $type: 4 instead of $type: 'array'. Notice that this solution doesn't even use $size, so there's no problem with indexes ("Queries cannot use indexes for the $size portion of a query")
Other solutions, including these (accepted answer):
ME.find({ pictures: { $exists: true, $not: {$size: 0} } });
ME.find({ pictures: { $exists: true, $ne: [] } })
are wrong because they return documents even if, for example, 'pictures' is null, undefined, 0, etc.
Stop all active ajax requests in jQuery
Using ajaxSetup is not correct, as is noted on its doc page. It only sets up defaults, and if some requests override them there will be a mess.
I am way late to the party, but just for future reference if someone is looking for a solution to the same problem, here is my go at it, inspired by and largely identical to the previous answers, but more complete
// Automatically cancel unfinished ajax requests
// when the user navigates elsewhere.
(function($) {
var xhrPool = [];
$(document).ajaxSend(function(e, jqXHR, options){
xhrPool.push(jqXHR);
});
$(document).ajaxComplete(function(e, jqXHR, options) {
xhrPool = $.grep(xhrPool, function(x){return x!=jqXHR});
});
var abort = function() {
$.each(xhrPool, function(idx, jqXHR) {
jqXHR.abort();
});
};
var oldbeforeunload = window.onbeforeunload;
window.onbeforeunload = function() {
var r = oldbeforeunload ? oldbeforeunload() : undefined;
if (r == undefined) {
// only cancel requests if there is no prompt to stay on the page
// if there is a prompt, it will likely give the requests enough time to finish
abort();
}
return r;
}
})(jQuery);
Index all *except* one item in python
I'm going to provide a functional (immutable) way of doing it.
The standard and easy way of doing it is to use slicing:
index_to_remove = 3
data = [*range(5)]
new_data = data[:index_to_remove] + data[index_to_remove + 1:]
print(f"data: {data}, new_data: {new_data}")
Output:
data: [0, 1, 2, 3, 4], new_data: [0, 1, 2, 4]
Use list comprehension:
data = [*range(5)]
new_data = [v for i, v in enumerate(data) if i != index_to_remove]
print(f"data: {data}, new_data: {new_data}")
Output:
data: [0, 1, 2, 3, 4], new_data: [0, 1, 2, 4]
Use filter function:
index_to_remove = 3
data = [*range(5)]
new_data = [*filter(lambda i: i != index_to_remove, data)]
Output:
data: [0, 1, 2, 3, 4], new_data: [0, 1, 2, 4]
Using masking. Masking is provided by itertools.compress function in the standard library:
from itertools import compress
index_to_remove = 3
data = [*range(5)]
mask = [1] * len(data)
mask[index_to_remove] = 0
new_data = [*compress(data, mask)]
print(f"data: {data}, mask: {mask}, new_data: {new_data}")
Output:
data: [0, 1, 2, 3, 4], mask: [1, 1, 1, 0, 1], new_data: [0, 1, 2, 4]
Use itertools.filterfalse function from Python standard library
from itertools import filterfalse
index_to_remove = 3
data = [*range(5)]
new_data = [*filterfalse(lambda i: i == index_to_remove, data)]
print(f"data: {data}, new_data: {new_data}")
Output:
data: [0, 1, 2, 3, 4], new_data: [0, 1, 2, 4]
Create directory if it does not exist
[System.IO.Directory]::CreateDirectory('full path to directory')
This internally checks for directory existence, and creates one, if there is no directory. Just one line and native .NET method working perfectly.
What is the difference between iterator and iterable and how to use them?
Consider an example having 10 apples.
When it implements Iterable, it is like putting each apple in boxes from 1 to 10 and return an iterator which can be used to navigate.
By implementing iterator, we can get any apple, apple in next boxes etc.
So implementing iterable gives an iterator to navigate its elements although to navigate, iterator needs to be implemented.
Fetch frame count with ffmpeg
You can use ffprobe to get frame number with the following commands
- first method
ffprobe.exe -i video_name -print_format json -loglevel fatal -show_streams -count_frames -select_streams v
which tell to print data in json format
select_streams v will tell ffprobe to just give us video stream data and if you remove it, it will give you audio information as well
and the output will be like
{
"streams": [
{
"index": 0,
"codec_name": "mpeg4",
"codec_long_name": "MPEG-4 part 2",
"profile": "Simple Profile",
"codec_type": "video",
"codec_time_base": "1/25",
"codec_tag_string": "mp4v",
"codec_tag": "0x7634706d",
"width": 640,
"height": 480,
"coded_width": 640,
"coded_height": 480,
"has_b_frames": 1,
"sample_aspect_ratio": "1:1",
"display_aspect_ratio": "4:3",
"pix_fmt": "yuv420p",
"level": 1,
"chroma_location": "left",
"refs": 1,
"quarter_sample": "0",
"divx_packed": "0",
"r_frame_rate": "10/1",
"avg_frame_rate": "10/1",
"time_base": "1/3000",
"start_pts": 0,
"start_time": "0:00:00.000000",
"duration_ts": 256500,
"duration": "0:01:25.500000",
"bit_rate": "261.816000 Kbit/s",
"nb_frames": "855",
"nb_read_frames": "855",
"disposition": {
"default": 1,
"dub": 0,
"original": 0,
"comment": 0,
"lyrics": 0,
"karaoke": 0,
"forced": 0,
"hearing_impaired": 0,
"visual_impaired": 0,
"clean_effects": 0,
"attached_pic": 0
},
"tags": {
"creation_time": "2005-10-17 22:54:33",
"language": "eng",
"handler_name": "Apple Video Media Handler",
"encoder": "3ivx D4 4.5.1"
}
}
]
}
2.
you can use
ffprobe -v error -show_format -show_streams video_name
which will give you stream data, if you want selected information like frame rate, use the following command
ffprobe -v error -select_streams v:0 -show_entries stream=avg_frame_rate -of default=noprint_wrappers=1:nokey=1 video_name
which give a number base on your video information, the problem is when you use this method, its possible you get a N/A as output.
for more information check this page FFProbe Tips
curl: (6) Could not resolve host: google.com; Name or service not known
I have today similar problem. But weirder.
- host - works
host pl.archive.ubuntu.com
- dig - works on default and on all other DNS's
dig pl.archive.ubuntu.com, dig @127.0.1.1 pl.archive.ubuntu.com
- curl - doesn't work! but for some addresses it does. WEIRD! Same in Ruby, APT and many more.
$ curl -v http://google.com/
* Trying 172.217.18.78...
* Connected to google.com (172.217.18.78) port 80 (#0)
> GET / HTTP/1.1
> Host: google.com
> User-Agent: curl/7.47.0
> Accept: */*
>
< HTTP/1.1 302 Found
< Cache-Control: private
< Content-Type: text/html; charset=UTF-8
< Referrer-Policy: no-referrer
< Location: http://www.google.pl/?gfe_rd=cr&ei=pt9UWfqXL4uBX_W5n8gB
< Content-Length: 256
< Date: Thu, 29 Jun 2017 11:08:22 GMT
<
<HTML><HEAD><meta http-equiv="content-type" content="text/html;charset=utf-8">
<TITLE>302 Moved</TITLE></HEAD><BODY>
<H1>302 Moved</H1>
The document has moved
<A HREF="http://www.google.pl/?gfe_rd=cr&ei=pt9UWfqXL4uBX_W5n8gB">here</A>.
</BODY></HTML>
* Connection #0 to host google.com left intact
$ curl -v http://pl.archive.ubuntu.com/
* Could not resolve host: pl.archive.ubuntu.com
* Closing connection 0
curl: (6) Could not resolve host: pl.archive.ubuntu.com
Revelation
Eventually I used strace on curl and found that it was connection to nscd deamon.
connect(4, {sa_family=AF_LOCAL, sun_path="/var/run/nscd/socket"}, 110) = 0
Solution
I've restarted the nscd service (Name Service Cache Daemon) and it helped to solve this issue!
systemctl restart nscd.service
Can I add extension methods to an existing static class?
You CAN do this if you are willing to "frig" it a little by making a variable of the static class and assigning it to null. However, this method would not be available to static calls on the class, so not sure how much use it would be:
Console myConsole = null;
myConsole.WriteBlueLine("my blue line");
public static class Helpers {
public static void WriteBlueLine(this Console c, string text)
{
Console.ForegroundColor = ConsoleColor.Blue;
Console.WriteLine(text);
Console.ResetColor();
}
}
phpMyAdmin + CentOS 6.0 - Forbidden
None of the configuration above worked for me on my CentOS 7 server. After hours of searching, that's what worked for me:
Edit file phpMyAdmin.conf
sudo nano /etc/httpd/conf.d/phpMyAdmin.conf
And replace this at the top:
<Directory /usr/share/phpMyAdmin/>
AddDefaultCharset UTF-8
<IfModule mod_authz_core.c>
# Apache 2.4
<RequireAny>
#Require ip 127.0.0.1
#Require ip ::1
Require all granted
</RequireAny>
</IfModule>
<IfModule !mod_authz_core.c>
# Apache 2.2
Order Deny,Allow
Deny from All
Allow from 127.0.0.1
Allow from ::1
</IfModule>
</Directory>
How to find most common elements of a list?
If you are using Count, or have created your own Count-style dict and want to show the name of the item and the count of it, you can iterate around the dictionary like so:
top_10_words = Counter(my_long_list_of_words)
# Iterate around the dictionary
for word in top_10_words:
# print the word
print word[0]
# print the count
print word[1]
or to iterate through this in a template:
{% for word in top_10_words %}
<p>Word: {{ word.0 }}</p>
<p>Count: {{ word.1 }}</p>
{% endfor %}
Hope this helps someone
Java; String replace (using regular expressions)?
If this is for any general math expression and parenthetical expressions are allowed, it will be very difficult (perhaps impossible) to do this with regular expressions.
If the only replacements are the ones you showed, it's not that hard to do. First strip out *'s, then use capturing like Can Berk Güder showed to handle the ^'s.
Make hibernate ignore class variables that are not mapped
For folks who find this posting through the search engines, another possible cause of this problem is from importing the wrong package version of @Transient. Make sure that you import javax.persistence.transient and not some other package.
How to find the minimum value of a column in R?
df <- read.table(text =
"X Y
1 2 3
2 4 5
3 6 7
4 8 9
5 10 11",
header = TRUE)
y_min <- min(df[,"Y"])
# Corresponding X value
x_val_associated <- df[df$Y == y_min, "X"]
x_val_associated
First, you find the Y min using the min function on the "Y" column only. Notice the returned result is just an integer value. Then, to find the associated X value, you can subset the data.frame to only the rows where the minimum Y value is located and extract just the "X" column.
You now have two integer values for X and Y where Y is the min.
Read text file into string array (and write)
func readToDisplayUsingFile1(f *os.File){
defer f.Close()
reader := bufio.NewReader(f)
contents, _ := ioutil.ReadAll(reader)
lines := strings.Split(string(contents), '\n')
}
or
func readToDisplayUsingFile1(f *os.File){
defer f.Close()
slice := make([]string,0)
reader := bufio.NewReader(f)
for{
str, err := reader.ReadString('\n')
if err == io.EOF{
break
}
slice = append(slice, str)
}
How do I create a shortcut via command-line in Windows?
I would like to propose different solution which wasn't mentioned here which is using .URL files:
set SHRT_LOCA=%userprofile%\Desktop\new_shortcut2.url
set SHRT_DEST=C:\Windows\write.exe
echo [InternetShortcut]> %SHRT_LOCA%
echo URL=file:///%SHRT_DEST%>> %SHRT_LOCA%
echo IconFile=%SHRT_DEST%>> %SHRT_LOCA%
echo IconIndex=^0>> %SHRT_LOCA%
Notes:
- By default
.url files are intended to open web pages but they are working fine for any properly constructed URI
- Microsoft Windows does not display the
.url file extension even if "Hide extensions for known file types" option in Windows Explorer is disabled
IconFile and IconIndex are optional- For reference you can check An Unofficial Guide to the URL File Format of Edward Blake
onClick not working on mobile (touch)
better to use touchstart event with .on() jQuery method:
$(window).load(function() { // better to use $(document).ready(function(){
$('.List li').on('click touchstart', function() {
$('.Div').slideDown('500');
});
});
And i don't understand why you are using $(window).load() method because it waits for everything on a page to be loaded, this tend to be slow, while you can use $(document).ready() method which does not wait for each element on the page to be loaded first.
What are the differences between struct and class in C++?
One other thing to note, if you updated a legacy app that had structs to use classes you might run into the following issue:
Old code has structs, code was cleaned up and these changed to classes.
A virtual function or two was then added to the new updated class.
When virtual functions are in classes then internally the compiler will add extra pointer to the class data to point to the functions.
How this would break old legacy code is if in the old code somewhere the struct was cleared using memfill to clear it all to zeros, this would stomp the extra pointer data as well.
How to change the default collation of a table?
It sets the default collation for the table; if you create a new column, that should be collated with latin_general_ci -- I think. Try specifying the collation for the individual column and see if that works. MySQL has some really bizarre behavior in regards to the way it handles this.
What's the difference between setWebViewClient vs. setWebChromeClient?
From the source code:
// Instance of WebViewClient that is the client callback.
private volatile WebViewClient mWebViewClient;
// Instance of WebChromeClient for handling all chrome functions.
private volatile WebChromeClient mWebChromeClient;
// SOME OTHER SUTFFF.......
/**
* Set the WebViewClient.
* @param client An implementation of WebViewClient.
*/
public void setWebViewClient(WebViewClient client) {
mWebViewClient = client;
}
/**
* Set the WebChromeClient.
* @param client An implementation of WebChromeClient.
*/
public void setWebChromeClient(WebChromeClient client) {
mWebChromeClient = client;
}
Using WebChromeClient allows you to handle Javascript dialogs, favicons, titles, and the progress. Take a look of this example: Adding alert() support to a WebView
At first glance, there are too many differences WebViewClient & WebChromeClient. But, basically: if you are developing a WebView that won't require too many features but rendering HTML, you can just use a WebViewClient. On the other hand, if you want to (for instance) load the favicon of the page you are rendering, you should use a WebChromeClient object and override the onReceivedIcon(WebView view, Bitmap icon).
Most of the times, if you don't want to worry about those things... you can just do this:
webView= (WebView) findViewById(R.id.webview);
webView.setWebChromeClient(new WebChromeClient());
webView.setWebViewClient(new WebViewClient());
webView.getSettings().setJavaScriptEnabled(true);
webView.loadUrl(url);
And your WebView will (in theory) have all features implemented (as the android native browser).
Program to find largest and second largest number in array
//I think its simple like
#include<stdio.h>
int main()
{
int a1[100],a2[100],i,t,l1,l2,n;
printf("Enter the number of elements:\n");
scanf("%d",&n);
printf("Enter the elements:\n");
for(i=0;i<n;i++)
{
scanf("%d",&a1[i]);
}
l1=a1[0];
for(i=0;i<n;i++)
{
if(a1[i]>=l1)
{
l1=a1[i];
t=i;
}
}
for(i=0;i<(n-1);i++)
{
if(i==t)
{
continue;
}
else
{
a2[i]=a1[i];
}
}
l2=a2[0];
for(i=1;i<(n-1);i++)
{
if(a2[i]>=l2 && a2[i]<l1)
{
l2=a2[i];
}
}
printf("Second highest number is %d",l2);
return 0;
}
Change color of Back button in navigation bar
Not sure why nobody has mentioned this...but I was doing exactly what you were doing in my viewDidLoad...and it wasn't working. Then I placed my code into viewWillAppear and it all worked.
The above solution is to change a single barbuttonItem. If you want to change the color for every navigationBar in your code then follow this answer.
Basically changing onto the class itself using appearance() is like making a global change on all instances of that view in your app. For more see here
Select distinct values from a large DataTable column
Method 1:
DataView view = new DataView(table);
DataTable distinctValues = view.ToTable(true, "id");
Method 2:
You will have to create a class matching your datatable column names and then you can use the following extension method to convert Datatable to List
public static List<T> ToList<T>(this DataTable table) where T : new()
{
List<PropertyInfo> properties = typeof(T).GetProperties().ToList();
List<T> result = new List<T>();
foreach (var row in table.Rows)
{
var item = CreateItemFromRow<T>((DataRow)row, properties);
result.Add(item);
}
return result;
}
private static T CreateItemFromRow<T>(DataRow row, List<PropertyInfo> properties) where T : new()
{
T item = new T();
foreach (var property in properties)
{
if (row.Table.Columns.Contains(property.Name))
{
if (row[property.Name] != DBNull.Value)
property.SetValue(item, row[property.Name], null);
}
}
return item;
}
and then you can get distinct from list using
YourList.Select(x => x.Id).Distinct();
Please note that this will return you complete Records and not just ids.
VNC viewer with multiple monitors
tightVNC 2.5.X and even pre 2.5 supports multi monitor.
When you connect, you get a huge virtual monitor.
However, this is also has disadvantages.
UltaVNC (Tho when I tried it, was buggy in this area) allows you to connect to one huge virtual monitor or just to 1 screen at a time. (With a button to cycle through them) TightVNC also plan to support such a feature.. (When , no idea)
This feature is important as if you have large multi monitors and connecting over a reasonably slow link.. The screen updates are just to slow..
Cutting down to one monitor to focus on is desirable.
I like tightVNC, but UltraVNC seems to have a few more features right now..
I have found tightVNC more solid. And that is why I have stuck with it.
I would try both. They both work well, but I imagine one would suite slightly more then the other.
How to build and fill pandas dataframe from for loop?
The simplest answer is what Paul H said:
d = []
for p in game.players.passing():
d.append(
{
'Player': p,
'Team': p.team,
'Passer Rating': p.passer_rating()
}
)
pd.DataFrame(d)
But if you really want to "build and fill a dataframe from a loop", (which, btw, I wouldn't recommend), here's how you'd do it.
d = pd.DataFrame()
for p in game.players.passing():
temp = pd.DataFrame(
{
'Player': p,
'Team': p.team,
'Passer Rating': p.passer_rating()
}
)
d = pd.concat([d, temp])
How to fix homebrew permissions?
Command from top-voted answer not work for me.
It got output:
chown: /usr/{my_username}dmin: illegal user name
This command works fine (group for /usr/local was admin already):
sudo chown -R $USER /usr/local
use std::fill to populate vector with increasing numbers
If you really want to use std::fill and are confined to C++98 you can use something like the following,
#include <algorithm>
#include <iterator>
#include <iostream>
#include <vector>
struct increasing {
increasing(int start) : x(start) {}
operator int () const { return x++; }
mutable int x;
};
int main(int argc, char* argv[])
{
using namespace std;
vector<int> v(10);
fill(v.begin(), v.end(), increasing(0));
copy(v.begin(), v.end(), ostream_iterator<int>(cout, " "));
cout << endl;
return 0;
}
Class constructor type in typescript?
How can I declare a class type, so that I ensure the object is a constructor of a general class?
A Constructor type could be defined as:
type AConstructorTypeOf<T> = new (...args:any[]) => T;
class A { ... }
function factory(Ctor: AConstructorTypeOf<A>){
return new Ctor();
}
const aInstance = factory(A);
When should you use 'friend' in C++?
As the reference for friend declaration says:
The friend declaration appears in a class body and grants a function or another class access to private and protected members of the class where the friend declaration appears.
So just as a reminder, there are technical errors in some of the answers which say that friend can only visit protected members.
How to center links in HTML
Try doing a nav element with a ul element. Mine has a main above but I don't think you need it.
<main>
<nav>
<ul><li><a href="http//www.google.com">search</a>
<li><a href="http//www.google.com">search</a>
<li><a href="http//www.google.com">search</a>
The code is something like this.
When ever I put in the code it wouldn't work right so you need to fill in the blank,
then center it.
main
nav
ul> li> a>: href="link of choice":name of link:/a>
How to change the name of an iOS app?
From Xcode 4.2 and onwards, you can use one more option.
Just click once on .proj file name at the top in left navigation pane and it will be available for renaming.Rename it and the whole project will get renamed and not only the target.
Load view from an external xib file in storyboard
My full example is here, but I will provide a summary below.
Layout
Add a .swift and .xib file each with the same name to your project. The .xib file contains your custom view layout (using auto layout constraints preferably).
Make the swift file the xib file's owner.
Code
Add the following code to the .swift file and hook up the outlets and actions from the .xib file.
import UIKit
class ResuableCustomView: UIView {
let nibName = "ReusableCustomView"
var contentView: UIView?
@IBOutlet weak var label: UILabel!
@IBAction func buttonTap(_ sender: UIButton) {
label.text = "Hi"
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
guard let view = loadViewFromNib() else { return }
view.frame = self.bounds
self.addSubview(view)
contentView = view
}
func loadViewFromNib() -> UIView? {
let bundle = Bundle(for: type(of: self))
let nib = UINib(nibName: nibName, bundle: bundle)
return nib.instantiate(withOwner: self, options: nil).first as? UIView
}
}
Use it
Use your custom view anywhere in your storyboard. Just add a UIView and set the class name to your custom class name.
For a while Christopher Swasey's approach was the best approach I had found. I asked a couple of the senior devs on my team about it and one of them had the perfect solution! It satisfies every one of the concerns that Christopher Swasey so eloquently addressed and it doesn't require boilerplate subclass code(my main concern with his approach). There is one gotcha, but other than that it is fairly intuitive and easy to implement.
- Create a custom UIView class in a .swift file to control your xib. i.e.
MyCustomClass.swift
- Create a .xib file and style it as you want. i.e.
MyCustomClass.xib
- Set the
File's Owner of the .xib file to be your custom class (MyCustomClass)
- GOTCHA: leave the
class value (under the identity Inspector) for your custom view in the .xib file blank. So your custom view will have no specified class, but it will have a specified File's Owner.
- Hook up your outlets as you normally would using the
Assistant Editor.
- NOTE: If you look at the
Connections Inspector you will notice that your Referencing Outlets do not reference your custom class (i.e. MyCustomClass), but rather reference File's Owner. Since File's Owner is specified to be your custom class, the outlets will hook up and work propery.
- Make sure your custom class has @IBDesignable before the class statement.
- Make your custom class conform to the
NibLoadable protocol referenced below.
- NOTE: If your custom class
.swift file name is different from your .xib file name, then set the nibName property to be the name of your .xib file.
- Implement
required init?(coder aDecoder: NSCoder) and override init(frame: CGRect) to call setupFromNib() like the example below.
- Add a UIView to your desired storyboard and set the class to be your custom class name (i.e.
MyCustomClass).
- Watch IBDesignable in action as it draws your .xib in the storyboard with all of it's awe and wonder.
Here is the protocol you will want to reference:
public protocol NibLoadable {
static var nibName: String { get }
}
public extension NibLoadable where Self: UIView {
public static var nibName: String {
return String(describing: Self.self)
}
public static var nib: UINib {
let bundle = Bundle(for: Self.self)
return UINib(nibName: Self.nibName, bundle: bundle)
}
func setupFromNib() {
guard let view = Self.nib.instantiate(withOwner: self, options: nil).first as? UIView else { fatalError("Error loading \(self) from nib") }
addSubview(view)
view.translatesAutoresizingMaskIntoConstraints = false
view.leadingAnchor.constraint(equalTo: self.safeAreaLayoutGuide.leadingAnchor, constant: 0).isActive = true
view.topAnchor.constraint(equalTo: self.safeAreaLayoutGuide.topAnchor, constant: 0).isActive = true
view.trailingAnchor.constraint(equalTo: self.safeAreaLayoutGuide.trailingAnchor, constant: 0).isActive = true
view.bottomAnchor.constraint(equalTo: self.safeAreaLayoutGuide.bottomAnchor, constant: 0).isActive = true
}
}
And here is an example of MyCustomClass that implements the protocol (with the .xib file being named MyCustomClass.xib):
@IBDesignable
class MyCustomClass: UIView, NibLoadable {
@IBOutlet weak var myLabel: UILabel!
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
setupFromNib()
}
override init(frame: CGRect) {
super.init(frame: frame)
setupFromNib()
}
}
NOTE: If you miss the Gotcha and set the class value inside your .xib file to be your custom class, then it will not draw in the storyboard and you will get a EXC_BAD_ACCESS error when you run the app because it gets stuck in an infinite loop of trying to initialize the class from the nib using the init?(coder aDecoder: NSCoder) method which then calls Self.nib.instantiate and calls the init again.
When does SQLiteOpenHelper onCreate() / onUpgrade() run?
SQLiteOpenHelper onCreate() and onUpgrade() callbacks are invoked when the database is actually opened, for example by a call to getWritableDatabase(). The database is not opened when the database helper object itself is created.
SQLiteOpenHelper versions the database files. The version number is the int argument passed to the constructor. In the database file, the version number is stored in PRAGMA user_version.
onCreate() is only run when the database file did not exist and was just created. If onCreate() returns successfully (doesn't throw an exception), the database is assumed to be created with the requested version number. As an implication, you should not catch SQLExceptions in onCreate() yourself.
onUpgrade() is only called when the database file exists but the stored version number is lower than requested in the constructor. The onUpgrade() should update the table schema to the requested version.
When changing the table schema in code (onCreate()), you should make sure the database is updated. Two main approaches:
Delete the old database file so that onCreate() is run again. This is often preferred at development time where you have control over the installed versions and data loss is not an issue. Some ways to delete the database file:
Increment the database version so that onUpgrade() is invoked. This is slightly more complicated as more code is needed.
For development time schema upgrades where data loss is not an issue, you can just use execSQL("DROP TABLE IF EXISTS <tablename>") in to remove your existing tables and call onCreate() to recreate the database.
For released versions, you should implement data migration in onUpgrade() so your users don't lose their data.
How to use Python requests to fake a browser visit a.k.a and generate User Agent?
I used fake UserAgent.
How to use:
from fake_useragent import UserAgent
import requests
ua = UserAgent()
print(ua.chrome)
header = {'User-Agent':str(ua.chrome)}
print(header)
url = "https://www.hybrid-analysis.com/recent-submissions?filter=file&sort=^timestamp"
htmlContent = requests.get(url, headers=header)
print(htmlContent)
Output:
Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_2) AppleWebKit/537.17 (KHTML, like Gecko) Chrome/24.0.1309.0 Safari/537.17
{'User-Agent': 'Mozilla/5.0 (X11; OpenBSD i386) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.125 Safari/537.36'}
<Response [200]>
Maven2 property that indicates the parent directory
So the problem as I see it is that you can't get the absolute path to a parent directory in maven.
<rant> I've heard this talked about as an anti-pattern, but for every anti-pattern there is real, legitimate use case for it, and I'm sick of maven telling me I can only follow their patterns.</rant>
So the work around I found was to use antrun. Try this in the child pom.xml:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-antrun-plugin</artifactId>
<version>1.7</version>
<executions>
<execution>
<id>getMainBaseDir</id>
<phase>validate</phase>
<goals>
<goal>run</goal>
</goals>
<configuration>
<exportAntProperties>true</exportAntProperties>
<target>
<!--Adjust the location below to your directory structure -->
<property name="main.basedir" location="./.." />
<echo message="main.basedir=${main.basedir}"/>
</target>
</configuration>
</execution>
</executions>
</plugin>
If you run mvn verify you should see something like this:
main:
[echo] main.basedir=C:\src\parent.project.dir.name
You can then use ${main.basedir} in any of the other plugins, etc. Took me a while to figure this out, so hope it helps someone else.
How to insert selected columns from a CSV file to a MySQL database using LOAD DATA INFILE
if you have number of columns in your database table more than number of columns in your csv you can proceed like this:
LOAD DATA LOCAL INFILE 'pathOfFile.csv'
INTO TABLE youTable
CHARACTER SET latin1 FIELDS TERMINATED BY ';' #you can use ',' if you have comma separated
OPTIONALLY ENCLOSED BY '"'
ESCAPED BY '\\'
LINES TERMINATED BY '\r\n'
(yourcolumn,yourcolumn2,yourcolumn3,yourcolumn4,...);
Jackson enum Serializing and DeSerializer
The serializer / deserializer solution pointed out by @xbakesx is an excellent one if you wish to completely decouple your enum class from its JSON representation.
Alternatively, if you prefer a self-contained solution, an implementation based on @JsonCreator and @JsonValue annotations would be more convenient.
So leveraging on the example by @Stanley the following is a complete self-contained solution (Java 6, Jackson 1.9):
public enum DeviceScheduleFormat {
Weekday,
EvenOdd,
Interval;
private static Map<String, DeviceScheduleFormat> namesMap = new HashMap<String, DeviceScheduleFormat>(3);
static {
namesMap.put("weekday", Weekday);
namesMap.put("even-odd", EvenOdd);
namesMap.put("interval", Interval);
}
@JsonCreator
public static DeviceScheduleFormat forValue(String value) {
return namesMap.get(StringUtils.lowerCase(value));
}
@JsonValue
public String toValue() {
for (Entry<String, DeviceScheduleFormat> entry : namesMap.entrySet()) {
if (entry.getValue() == this)
return entry.getKey();
}
return null; // or fail
}
}
XML Parsing - Read a Simple XML File and Retrieve Values
Try XmlSerialization
try this
[Serializable]
public class Task
{
public string Name{get; set;}
public string Location {get; set;}
public string Arguments {get; set;}
public DateTime RunWhen {get; set;}
}
public void WriteXMl(Task task)
{
XmlSerializer serializer;
serializer = new XmlSerializer(typeof(Task));
MemoryStream stream = new MemoryStream();
StreamWriter writer = new StreamWriter(stream, Encoding.Unicode);
serializer.Serialize(writer, task);
int count = (int)stream.Length;
byte[] arr = new byte[count];
stream.Seek(0, SeekOrigin.Begin);
stream.Read(arr, 0, count);
using (BinaryWriter binWriter=new BinaryWriter(File.Open(@"C:\Temp\Task.xml", FileMode.Create)))
{
binWriter.Write(arr);
}
}
public Task GetTask()
{
StreamReader stream = new StreamReader(@"C:\Temp\Task.xml", Encoding.Unicode);
return (Task)serializer.Deserialize(stream);
}
How do you split and unsplit a window/view in Eclipse IDE?
This is possible with the menu items Window>Editor>Toggle Split Editor.
Current shortcut for splitting is:
Azerty keyboard:
- Ctrl + _ for split horizontally, and
- Ctrl + { for split vertically.
Qwerty US keyboard:
- Ctrl + Shift + - (accessing _) for split horizontally, and
- Ctrl + Shift + [ (accessing {) for split vertically.
MacOS - Qwerty US keyboard:
- ⌘ + Shift + - (accessing _) for split horizontally, and
- ⌘ + Shift + [ (accessing {) for split vertically.
On any other keyboard if a required key is unavailable (like { on a german Qwertz keyboard), the following generic approach may work:
- Alt + ASCII code + Ctrl then release Alt
Example: ASCII for '{' = 123, so press 'Alt', '1', '2', '3', 'Ctrl' and release 'Alt', effectively typing '{' while 'Ctrl' is pressed, to split vertically.
Example of vertical split:
PS:
- The menu items Window>Editor>Toggle Split Editor were added with Eclipse Luna 4.4 M4, as mentioned by Lars Vogel in "Split editor implemented in Eclipse M4 Luna"
- The split editor is one of the oldest and most upvoted Eclipse bug! Bug 8009
- The split editor functionality has been developed in Bug 378298, and will be available as of Eclipse Luna M4. The Note & Newsworthy of Eclipse Luna M4 will contain the announcement.
How to show Page Loading div until the page has finished loading?
This script will add a div that covers the entire window as the page loads. It will show a CSS-only loading spinner automatically. It will wait until the window (not the document) finishes loading, then it will wait an optional extra few seconds.
- Works with jQuery 3 (it has a new window load event)
- No image needed but it's easy to add one
- Change the delay for more branding or instructions
- Only dependency is jQuery.
CSS loader code from https://projects.lukehaas.me/css-loaders
_x000D_
_x000D_
_x000D_
$('body').append('<div style="" id="loadingDiv"><div class="loader">Loading...</div></div>');_x000D_
$(window).on('load', function(){_x000D_
setTimeout(removeLoader, 2000); //wait for page load PLUS two seconds._x000D_
});_x000D_
function removeLoader(){_x000D_
$( "#loadingDiv" ).fadeOut(500, function() {_x000D_
// fadeOut complete. Remove the loading div_x000D_
$( "#loadingDiv" ).remove(); //makes page more lightweight _x000D_
}); _x000D_
}
_x000D_
.loader,_x000D_
.loader:after {_x000D_
border-radius: 50%;_x000D_
width: 10em;_x000D_
height: 10em;_x000D_
}_x000D_
.loader { _x000D_
margin: 60px auto;_x000D_
font-size: 10px;_x000D_
position: relative;_x000D_
text-indent: -9999em;_x000D_
border-top: 1.1em solid rgba(255, 255, 255, 0.2);_x000D_
border-right: 1.1em solid rgba(255, 255, 255, 0.2);_x000D_
border-bottom: 1.1em solid rgba(255, 255, 255, 0.2);_x000D_
border-left: 1.1em solid #ffffff;_x000D_
-webkit-transform: translateZ(0);_x000D_
-ms-transform: translateZ(0);_x000D_
transform: translateZ(0);_x000D_
-webkit-animation: load8 1.1s infinite linear;_x000D_
animation: load8 1.1s infinite linear;_x000D_
}_x000D_
@-webkit-keyframes load8 {_x000D_
0% {_x000D_
-webkit-transform: rotate(0deg);_x000D_
transform: rotate(0deg);_x000D_
}_x000D_
100% {_x000D_
-webkit-transform: rotate(360deg);_x000D_
transform: rotate(360deg);_x000D_
}_x000D_
}_x000D_
@keyframes load8 {_x000D_
0% {_x000D_
-webkit-transform: rotate(0deg);_x000D_
transform: rotate(0deg);_x000D_
}_x000D_
100% {_x000D_
-webkit-transform: rotate(360deg);_x000D_
transform: rotate(360deg);_x000D_
}_x000D_
}_x000D_
#loadingDiv {_x000D_
position:absolute;;_x000D_
top:0;_x000D_
left:0;_x000D_
width:100%;_x000D_
height:100%;_x000D_
background-color:#000;_x000D_
}
_x000D_
This script will add a div that covers the entire window as the page loads. It will show a CSS-only loading spinner automatically. It will wait until the window (not the document) finishes loading._x000D_
_x000D_
<ul>_x000D_
<li>Works with jQuery 3, which has a new window load event</li>_x000D_
<li>No image needed but it's easy to add one</li>_x000D_
<li>Change the delay for branding or instructions</li>_x000D_
<li>Only dependency is jQuery.</li>_x000D_
</ul>_x000D_
_x000D_
Place the script below at the bottom of the body._x000D_
_x000D_
CSS loader code from https://projects.lukehaas.me/css-loaders_x000D_
_x000D_
<!-- Place the script below at the bottom of the body -->_x000D_
_x000D_
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
_x000D_
_x000D_
_x000D_
Add new element to an existing object
You could store your JSON inside of an array and then insert the JSON data into the array with push
Check this out https://jsfiddle.net/cx2rk40e/2/
$(document).ready(function(){
// using jQuery just to load function but will work without library.
$( "button" ).on( "click", go );
// Array of JSON we will append too.
var jsonTest = [{
"colour": "blue",
"link": "http1"
}]
// Appends JSON to array with push. Then displays the data in alert.
function go() {
jsonTest.push({"colour":"red", "link":"http2"});
alert(JSON.stringify(jsonTest));
}
});
Result of JSON.stringify(jsonTest)
[{"colour":"blue","link":"http1"},{"colour":"red","link":"http2"}]
This answer maybe useful to users who wish to emulate a similar result.
Pretty Printing JSON with React
You'll need to either insert BR tag appropriately in the resulting string, or use for example a PRE tag so that the formatting of the stringify is retained:
var data = { a: 1, b: 2 };
var Hello = React.createClass({
render: function() {
return <div><pre>{JSON.stringify(data, null, 2) }</pre></div>;
}
});
React.render(<Hello />, document.getElementById('container'));
Working example.
Update
class PrettyPrintJson extends React.Component {
render() {
// data could be a prop for example
// const { data } = this.props;
return (<div><pre>{JSON.stringify(data, null, 2) }</pre></div>);
}
}
ReactDOM.render(<PrettyPrintJson/>, document.getElementById('container'));
Stateless Functional component, React .14 or higher
const PrettyPrintJson = ({data}) => {
// (destructured) data could be a prop for example
return (<div><pre>{ JSON.stringify(data, null, 2) }</pre></div>);
}
Or, ...
const PrettyPrintJson = ({data}) => (<div><pre>{
JSON.stringify(data, null, 2) }</pre></div>);
Working example
Memo / 16.6+
(You might even want to use a memo, 16.6+)
const PrettyPrintJson = React.memo(({data}) => (<div><pre>{
JSON.stringify(data, null, 2) }</pre></div>));
C# DateTime.ParseExact
try this
var insert = DateTime.ParseExact(line[i], "M/d/yyyy h:mm", CultureInfo.InvariantCulture);
Array to String PHP?
$data = array("asdcasdc","35353","asdca353sdc","sadcasdc","sadcasdc","asdcsdcsad");
$string_array = json_encode($data);
now you can insert this $string_array value into Database
Render HTML to an image
I know this is quite an old question which already has a lot of answers, yet I still spent hours trying to actually do what I wanted:
- given an html file, generate a (png) image with transparent background from the command line
Using Chrome headless (version 74.0.3729.157 as of this response), it is actually easy:
"/Applications/Google Chrome.app/Contents/MacOS/Google Chrome" --headless --screenshot --window-size=256,256 --default-background-color=0 button.html
Explanation of the command:
- you run Chrome from the command line (here shown for the Mac, but assuming similar on Windows or Linux)
--headless runs Chrome without opening it and exits after the command completes--screenshot will capture a screenshot (note that it generates a file called screenshot.png in the folder where the command is run)--window-size allow to only capture a portion of the screen (format is --window-size=width,height)--default-background-color=0 is the magic trick that tells Chrome to use a transparent background, not the default white color- finally you provide the html file (as a url either local or remote...)
How to enable bulk permission in SQL Server
SQL Server may also return this error if the service account does not have permission to read the file being imported. Ensure that the service account has read access to the file location. For example:
icacls D:\ImportFiles /Grant "NT Service\MSSQLServer":(OI)(CI)R
jquery animate .css
Just use .animate() instead of .css() (with a duration if you want), like this:
$('#hfont1').hover(function() {
$(this).animate({"color":"#efbe5c","font-size":"52pt"}, 1000);
}, function() {
$(this).animate({"color":"#e8a010","font-size":"48pt"}, 1000);
});
You can test it here. Note though, you need either the jQuery color plugin, or jQuery UI included to animate the color. In the above, the duration is 1000ms, you can change it, or just leave it off for the default 400ms duration.
MongoDB - admin user not authorized
I followed these steps on Centos 7 for MongoDB 4.2. (Remote user)
Update mongod.conf file
vi /etc/mongod.conf
net:
port: 27017
bindIp: 0.0.0.0
security:
authorization: enabled
Start MongoDB service demon
systemctl start mongod
Open MongoDB shell
mongo
Execute this command on the shell
use admin
db.createUser(
{
user: 'admin',
pwd: 'YouPassforUser',
roles: [ { role: 'root', db: 'admin' } ]
}
);
Remote root user has been created. Now you can test this database connection by using any MongoDB GUI tool from your dev machine. Like Robo 3T
Node.js: How to send headers with form data using request module?
I think it's just because you have forgot HTTP METHOD. The default HTTP method of request is GET.
You should add method: 'POST' and your code will work if your backend receive the post method.
var req = require('request');
req.post({
url: 'someUrl',
form: { username: 'user', password: '', opaque: 'someValue', logintype: '1'},
headers: {
'User-Agent': 'Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.110 Safari/537.36',
'Content-Type' : 'application/x-www-form-urlencoded'
},
method: 'POST'
},
function (e, r, body) {
console.log(body);
});
Change onclick action with a Javascript function
Your code is calling the function and assigning the return value to onClick, also it should be 'onclick'. This is how it should look.
document.getElementById("a").onclick = Bar;
Looking at your other code you probably want to do something like this:
document.getElementById(id+"Button").onclick = function() { HideError(id); }
Adding values to Arraylist
There's a faster and easy way in Java 9 without involving much of code: Using Collection Factory methods:
List<String> list = List.of("first", "second", "third");
difference between throw and throw new Exception()
throw or throw ex, both are used to throw or rethrow the exception, when you just simply log the error information and don't want to send any information back to the caller you simply log the error in catch and leave. But incase you want to send some meaningful information about the exception to the caller you use throw or throw ex. Now the difference between throw and throw ex is that throw preserves the stack trace and other information but throw ex creates a new exception object and hence the original stack trace is lost.
So when should we use throw and throw e, There are still a few situations in which you might want to rethrow an exception like to reset the call stack information. For example, if the method is in a library and you want to hide the details of the library from the calling code, you don’t necessarily want the call stack to include information about private methods within the library. In that case, you could catch exceptions in the library’s public methods and then rethrow them so that the call stack begins at those public methods.
jQuery-- Populate select from json
Only change the DOM once...
var listitems = '';
$.each(temp, function(key, value){
listitems += '<option value=' + key + '>' + value + '</option>';
});
$select.append(listitems);
HTML5 Form Input Pattern Currency Format
I like to give the users a bit of flexibility and trust, that they will get the format right, but I do want to enforce only digits and two decimals for currency
^[$\-\s]*[\d\,]*?([\.]\d{0,2})?\s*$
Takes care of:
$ 1.
-$ 1.00
$ -1.0
.1
.10
-$ 1,000,000.0
Of course it will also match:
$$--$1,92,9,29.1 => anyway after cleanup => -192,929.10
Linux/Unix command to determine if process is running?
You SHOULD know the PID !
Finding a process by trying to do some kind of pattern recognition on the process arguments (like pgrep "mysqld") is a strategy that is doomed to fail sooner or later. What if you have two mysqld running? Forget that approach. You MAY get it right temporarily and it MAY work for a year or two but then something happens that you haven't thought about.
Only the process id (pid) is truly unique.
Always store the pid when you launch something in the background. In Bash this can be done with the $! Bash variable. You will save yourself SO much trouble by doing so.
How to determine if process is running (by pid)
So now the question becomes how to know if a pid is running.
Simply do:
ps -o pid= -p <pid>
This is POSIX and hence portable. It will return the pid itself if the process is running or return nothing if the process is not running. Strictly speaking the command will return a single column, the pid, but since we've given that an empty title header (the stuff immediately preceding the equals sign) and this is the only column requested then the ps command will not use header at all. Which is what we want because it makes parsing easier.
This will work on Linux, BSD, Solaris, etc.
Another strategy would be to test on the exit value from the above ps command. It should be zero if the process is running and non-zero if it isn't. The POSIX spec says that ps must exit >0 if an error has occurred but it is unclear to me what constitutes 'an error'. Therefore I'm not personally using that strategy although I'm pretty sure it will work as well on all Unix/Linux platforms.
Apache Server (xampp) doesn't run on Windows 10 (Port 80)
This answer is intended as an addendum to the highest rated answer on this thread by paaacman. I just wanted to add some helpful detail for users like myself who don't know their way around Windows 10 as well.
Windows 10 runs IIS (Internet Information Services, Microsoft's web server software) automatically during Startup on Port 80. In order to use Apache Server on that port, IIS must be stopped.
paaacman's response refers to the IIS server as "W3SVC", or the "World Wide Web Publishing Service". I suppose that's because Windows 10 runs IIS as a service. In order to disable it or modify how the service runs, you need to know where to find "Services" in your system.
I found the easiest way there was to click on the search button next to the start menu button in the Windows 10 taskbar and type "Administrative Tools". You can either hit return or click on the "Administrative Tools" link that Windows finds for you.
A control panel window will open with a list of tools. The one you want is "Services." Double-click it.
Another window will open called "Services." Locate the one named "World Wide Web Publishing Service." Some other users in this thread have listed what it is called in other languages, if your list is not in English.
If you only want to turn off the IIS server for this Windows session, but want it to run automatically again the next time you start up Windows, right-click "World Wide Web Publishing Service" and choose "Stop." The server will stop, and Port 80 will be freed up for Apache (or whatever else you want to use it for).
If you want to prevent the IIS server from running automatically when you start up Windows in the future, right-click "World Wide Web Publishing Serivce" and select "Properties." In the window that appears, locate the "Startup type" dropdown, and set it "Manual." Click "Apply" or "OK" to save your changes. You should be all set.
What is a race condition?
A race condition is a kind of bug, that happens only with certain temporal conditions.
Example:
Imagine you have two threads, A and B.
In Thread A:
if( object.a != 0 )
object.avg = total / object.a
In Thread B:
object.a = 0
If thread A is preempted just after having check that object.a is not null, B will do a = 0, and when thread A will gain the processor, it will do a "divide by zero".
This bug only happen when thread A is preempted just after the if statement, it's very rare, but it can happen.
Get all mysql selected rows into an array
I would suggest the use of MySQLi or MySQL PDO for performance and security purposes, but to answer the question:
while($row = mysql_fetch_assoc($result)){
$json[] = $row;
}
echo json_encode($json);
If you switched to MySQLi you could do:
$query = "SELECT * FROM table";
$result = mysqli_query($db, $query);
$json = mysqli_fetch_all ($result, MYSQLI_ASSOC);
echo json_encode($json );
Replacing few values in a pandas dataframe column with another value
Replace
DataFrame object has powerful and flexible replace method:
DataFrame.replace(
to_replace=None,
value=None,
inplace=False,
limit=None,
regex=False,
method='pad',
axis=None)
Note, if you need to make changes in place, use inplace boolean argument for replace method:
Inplace
inplace: boolean, default False
If True, in place. Note: this will modify any other views on this object (e.g. a column form a DataFrame). Returns the caller if this is True.
Snippet
df['BrandName'].replace(
to_replace=['ABC', 'AB'],
value='A',
inplace=True
)
Chrome extension: accessing localStorage in content script
Update 2016:
Google Chrome released the storage API: http://developer.chrome.com/extensions/storage.html
It is pretty easy to use like the other Chrome APIs and you can use it from any page context within Chrome.
// Save it using the Chrome extension storage API.
chrome.storage.sync.set({'foo': 'hello', 'bar': 'hi'}, function() {
console.log('Settings saved');
});
// Read it using the storage API
chrome.storage.sync.get(['foo', 'bar'], function(items) {
message('Settings retrieved', items);
});
To use it, make sure you define it in the manifest:
"permissions": [
"storage"
],
There are methods to "remove", "clear", "getBytesInUse", and an event listener to listen for changed storage "onChanged"
Using native localStorage (old reply from 2011)
Content scripts run in the context of webpages, not extension pages. Therefore, if you're accessing localStorage from your contentscript, it will be the storage from that webpage, not the extension page storage.
Now, to let your content script to read your extension storage (where you set them from your options page), you need to use extension message passing.
The first thing you do is tell your content script to send a request to your extension to fetch some data, and that data can be your extension localStorage:
contentscript.js
chrome.runtime.sendMessage({method: "getStatus"}, function(response) {
console.log(response.status);
});
background.js
chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
if (request.method == "getStatus")
sendResponse({status: localStorage['status']});
else
sendResponse({}); // snub them.
});
You can do an API around that to get generic localStorage data to your content script, or perhaps, get the whole localStorage array.
I hope that helped solve your problem.
To be fancy and generic ...
contentscript.js
chrome.runtime.sendMessage({method: "getLocalStorage", key: "status"}, function(response) {
console.log(response.data);
});
background.js
chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
if (request.method == "getLocalStorage")
sendResponse({data: localStorage[request.key]});
else
sendResponse({}); // snub them.
});
How does the communication between a browser and a web server take place?
The links for specifications of each aspect of the question is as follows:
GET, POST verbs (among others) - The HTTP Specification exhaustively discusses all aspects of HTTP communication (the protocol for communication between the web server and the browser). It explains the Request message and Response message protocols.
Cookies - are set by attaching a Set-Cookie HTTP Header to the HTTP response.
QueryStrings - are the part of the URL in the HTTP request that follow the first occurrence of a "?" character. The linked specification is for section 3.4 of the URI specification.
Sessions - HTTP is a synchronous, stateless protocol. Sessions, or the illusion of state, can be created by (1) using cookies to store state data as plain text on the client's computer, (2) passing data-values in the URL and querystring of the request, (3) submitting POST requests with a collection of values that may indicate state and, (4) storing state information by a server-side persistence mechanism that is retrieved by a session-key (the session key is resolved from either the cookie, URL/Querystring or POST value collection.
An explanation of HTTP can go on for days, but I have attempted to provide a concise yet conceptually complete answer, and include the appropriate links for further reading of official specifications.
pop/remove items out of a python tuple
As DSM mentions, tuple's are immutable, but even for lists, a more elegant solution is to use filter:
tupleX = filter(str.isdigit, tupleX)
or, if condition is not a function, use a comprehension:
tupleX = [x for x in tupleX if x > 5]
if you really need tupleX to be a tuple, use a generator expression and pass that to tuple:
tupleX = tuple(x for x in tupleX if condition)
PHP, MySQL error: Column count doesn't match value count at row 1
The number of column parameters in your insert query is 9, but you've only provided 8 values.
INSERT INTO dbname (id, Name, Description, shortDescription, Ingredients, Method, Length, dateAdded, Username) VALUES ('', '%s', '%s', '%s', '%s', '%s', '%s', '%s')
The query should omit the "id" parameter, because it is auto-generated (or should be anyway):
INSERT INTO dbname (Name, Description, shortDescription, Ingredients, Method, Length, dateAdded, Username) VALUES ('', '%s', '%s', '%s', '%s', '%s', '%s', '%s')
CSS height 100% percent not working
I believe you need to make sure that all the container div tags above the 100% height div also has 100% height set on them including the body tag and html.
"Cannot send session cache limiter - headers already sent"
"Headers already sent" means that your PHP script already sent the HTTP headers, and as such it can't make modifications to them now.
Check that you don't send ANY content before calling session_start. Better yet, just make session_start the first thing you do in your PHP file (so put it at the absolute beginning, before all HTML etc).
How to bind WPF button to a command in ViewModelBase?
<Grid >
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*"/>
</Grid.ColumnDefinitions>
<Button Command="{Binding ClickCommand}" Width="100" Height="100" Content="wefwfwef"/>
</Grid>
the code behind for the window:
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
DataContext = new ViewModelBase();
}
}
The ViewModel:
public class ViewModelBase
{
private ICommand _clickCommand;
public ICommand ClickCommand
{
get
{
return _clickCommand ?? (_clickCommand = new CommandHandler(() => MyAction(), ()=> CanExecute));
}
}
public bool CanExecute
{
get
{
// check if executing is allowed, i.e., validate, check if a process is running, etc.
return true/false;
}
}
public void MyAction()
{
}
}
Command Handler:
public class CommandHandler : ICommand
{
private Action _action;
private Func<bool> _canExecute;
/// <summary>
/// Creates instance of the command handler
/// </summary>
/// <param name="action">Action to be executed by the command</param>
/// <param name="canExecute">A bolean property to containing current permissions to execute the command</param>
public CommandHandler(Action action, Func<bool> canExecute)
{
_action = action;
_canExecute = canExecute;
}
/// <summary>
/// Wires CanExecuteChanged event
/// </summary>
public event EventHandler CanExecuteChanged
{
add { CommandManager.RequerySuggested += value; }
remove { CommandManager.RequerySuggested -= value; }
}
/// <summary>
/// Forcess checking if execute is allowed
/// </summary>
/// <param name="parameter"></param>
/// <returns></returns>
public bool CanExecute(object parameter)
{
return _canExecute.Invoke();
}
public void Execute(object parameter)
{
_action();
}
}
I hope this will give you the idea.
How do I link to part of a page? (hash?)
You use an anchor and a hash. For example:
Target of the Link:
<a name="name_of_target">Content</a>
Link to the Target:
<a href="#name_of_target">Link Text</a>
Or, if linking from a different page:
<a href="http://path/to/page/#name_of_target">Link Text</a>
Programmatically Lighten or Darken a hex color (or rgb, and blend colors)
I've long wanted to be able to produce tints/shades of colours, here is my JavaScript solution:
const varyHue = function (hueIn, pcIn) {
const truncate = function (valIn) {
if (valIn > 255) {
valIn = 255;
} else if (valIn < 0) {
valIn = 0;
}
return valIn;
};
let red = parseInt(hueIn.substring(0, 2), 16);
let green = parseInt(hueIn.substring(2, 4), 16);
let blue = parseInt(hueIn.substring(4, 6), 16);
let pc = parseInt(pcIn, 10); //shade positive, tint negative
let max = 0;
let dif = 0;
max = red;
if (pc < 0) { //tint: make lighter
if (green < max) {
max = green;
}
if (blue < max) {
max = blue;
}
dif = parseInt(((Math.abs(pc) / 100) * (255 - max)), 10);
return leftPad(((truncate(red + dif)).toString(16)), '0', 2) + leftPad(((truncate(green + dif)).toString(16)), '0', 2) + leftPad(((truncate(blue + dif)).toString(16)), '0', 2);
} else { //shade: make darker
if (green > max) {
max = green;
}
if (blue > max) {
max = blue;
}
dif = parseInt(((pc / 100) * max), 10);
return leftPad(((truncate(red - dif)).toString(16)), '0', 2) + leftPad(((truncate(green - dif)).toString(16)), '0', 2) + leftPad(((truncate(blue - dif)).toString(16)), '0', 2);
}
};
How to select the last column of dataframe
These are few things which will help you in understanding everything... using iloc
In iloc, [initial row:ending row, initial column:ending column]
case 1: if you want only last column --- df.iloc[:,-1] & df.iloc[:,-1:]
this means that you want only the last column...
case 2: if you want all columns and all rows except the last column --- df.iloc[:,:-1]
this means that you want all columns and all rows except the last column...
case 3: if you want only last row --- df.iloc[-1:,:] & df.iloc[-1,:]
this means that you want only the last row...
case 4: if you want all columns and all rows except the last row --- df.iloc[:-1,:]
this means that you want all columns and all rows except the last column...
case 5: if you want all columns and all rows except the last row and last column --- df.iloc[:-1,:-1]
this means that you want all columns and all rows except the last column and last row...
Obtain smallest value from array in Javascript?
function tinyFriends() {
let myFriends = ["Mukit", "Ali", "Umor", "sabbir"]
let smallestFridend = myFriends[0];
for (i = 0; i < myFriends.length; i++) {
if (myFriends[i] < smallestFridend) {
smallestFridend = myFriends[i];
}
}
return smallestFridend
}
Detect touch press vs long press vs movement?
I was looking for a similar solution and this is what I would suggest.
In the OnTouch method, record the time for MotionEvent.ACTION_DOWN event and then for MotionEvent.ACTION_UP, record the time again. This way you can set your own threshold also. After experimenting few times you will know the max time in millis it would need to record a simple touch and you can use this in move or other method as you like.
Hope this helped. Please comment if you used a different method and solved your problem.
How do I display local image in markdown?
You may find following the syntax similar to reference links in markdown handy, especially when you have a text with many displays of the same image:
![optional text description of the image][number]
[number]: URL
For example:
![][1]
![This is an optional description][2]
[1]: /home/jerzy/ComputerScience/Parole/Screenshot_2020-10-13_11-53-29.png
[2]: /home/jerzy/ComputerScience/Parole/Screenshot_2020-10-13_11-53-30.png
How to use fetch in typescript
A few examples follow, going from basic through to adding transformations after the request and/or error handling:
Basic:
// Implementation code where T is the returned data shape
function api<T>(url: string): Promise<T> {
return fetch(url)
.then(response => {
if (!response.ok) {
throw new Error(response.statusText)
}
return response.json<T>()
})
}
// Consumer
api<{ title: string; message: string }>('v1/posts/1')
.then(({ title, message }) => {
console.log(title, message)
})
.catch(error => {
/* show error message */
})
Data transformations:
Often you may need to do some tweaks to the data before its passed to the consumer, for example, unwrapping a top level data attribute. This is straight forward:
function api<T>(url: string): Promise<T> {
return fetch(url)
.then(response => {
if (!response.ok) {
throw new Error(response.statusText)
}
return response.json<{ data: T }>()
})
.then(data => { /* <-- data inferred as { data: T }*/
return data.data
})
}
// Consumer - consumer remains the same
api<{ title: string; message: string }>('v1/posts/1')
.then(({ title, message }) => {
console.log(title, message)
})
.catch(error => {
/* show error message */
})
Error handling:
I'd argue that you shouldn't be directly error catching directly within this service, instead, just allowing it to bubble, but if you need to, you can do the following:
function api<T>(url: string): Promise<T> {
return fetch(url)
.then(response => {
if (!response.ok) {
throw new Error(response.statusText)
}
return response.json<{ data: T }>()
})
.then(data => {
return data.data
})
.catch((error: Error) => {
externalErrorLogging.error(error) /* <-- made up logging service */
throw error /* <-- rethrow the error so consumer can still catch it */
})
}
// Consumer - consumer remains the same
api<{ title: string; message: string }>('v1/posts/1')
.then(({ title, message }) => {
console.log(title, message)
})
.catch(error => {
/* show error message */
})
Edit
There has been some changes since writing this answer a while ago. As mentioned in the comments, response.json<T> is no longer valid. Not sure, couldn't find where it was removed.
For later releases, you can do:
// Standard variation
function api<T>(url: string): Promise<T> {
return fetch(url)
.then(response => {
if (!response.ok) {
throw new Error(response.statusText)
}
return response.json() as Promise<T>
})
}
// For the "unwrapping" variation
function api<T>(url: string): Promise<T> {
return fetch(url)
.then(response => {
if (!response.ok) {
throw new Error(response.statusText)
}
return response.json() as Promise<{ data: T }>
})
.then(data => {
return data.data
})
}
Merging 2 branches together in GIT
merge is used to bring two (or more) branches together.
a little example:
# on branch A:
# create new branch B
$ git checkout -b B
# hack hack
$ git commit -am "commit on branch B"
# create new branch C from A
$ git checkout -b C A
# hack hack
$ git commit -am "commit on branch C"
# go back to branch A
$ git checkout A
# hack hack
$ git commit -am "commit on branch A"
so now there are three separate branches (namely A B and C) with different heads
to get the changes from B and C back to A, checkout A (already done in this example) and then use the merge command:
# create an octopus merge
$ git merge B C
your history will then look something like this:
…-o-o-x-------A
|\ /|
| B---/ |
\ /
C---/
if you want to merge across repository/computer borders, have a look at git pull command, e.g. from the pc with branch A (this example will create two new commits):
# pull branch B
$ git pull ssh://host/… B
# pull branch C
$ git pull ssh://host/… C
How do I get a substring of a string in Python?
a="Helloo"
print(a[:-1])
In the above code, [:-1] declares to print from the starting till the maximum limit-1.
OUTPUT :
>>> Hello
Note: Here a [:-1] is also the same as a [0:-1] and a [0:len(a)-1]
a="I Am Siva"
print(a[2:])
OUTPUT:
>>> Am Siva
In the above code a [2:] declares to print a from index 2 till the last element.
Remember that if you set the maximum limit to print a string, as (x) then it will print the string till (x-1) and also remember that the index of a list or string will always start from 0.
How to install mcrypt extension in xampp
The recent versions of XAMPP for Windows runs PHP 7.x which are NOT compatible with mbcrypt.
If you have a package like Laravel that requires mbcrypt, you will need to install an older version of XAMPP. OR, you can run XAMPP with multiple versions of PHP by downloading a PHP package from Windows.PHP.net, installing it in your XAMPP folder, and configuring php.ini and httpd.conf to use the correct version of PHP for your site.
Insertion sort vs Bubble Sort Algorithms
insertion sort:
1.In the insertion sort swapping is not required.
2.the time complexity of insertion sort is O(n)for best case and O(n^2) worst case.
3.less complex as compared to bubble sort.
4.example: insert books in library, arrange cards.
bubble sort:
1.Swapping required in bubble sort.
2.the time complexity of bubble sort is O(n)for best case and O(n^2) worst case.
3.more complex as compared to insertion sort.
Parsing JSON Object in Java
1.) Create an arraylist of appropriate type, in this case i.e String
2.) Create a JSONObject while passing your string to JSONObject constructor as input
- As
JSONObject notation is represented by braces i.e {}
- Where as
JSONArray notation is represented by square brackets i.e []
3.) Retrieve JSONArray from JSONObject (created at 2nd step) using "interests" as index.
4.) Traverse JASONArray using loops upto the length of array provided by length() function
5.) Retrieve your JSONObjects from JSONArray using getJSONObject(index) function
6.) Fetch the data from JSONObject using index '"interestKey"'.
Note : JSON parsing uses the escape sequence for special nested characters if the json response (usually from other JSON response APIs) contains quotes (") like this
`"{"key":"value"}"`
should be like this
`"{\"key\":\"value\"}"`
so you can use JSONParser to achieve escaped sequence format for safety as
JSONParser parser = new JSONParser();
JSONObject json = (JSONObject) parser.parse(inputString);
Code :
JSONParser parser = new JSONParser();
String response = "{interests : [{interestKey:Dogs}, {interestKey:Cats}]}";
JSONObject jsonObj = (JSONObject) parser.parse(response);
or
JSONObject jsonObj = new JSONObject("{interests : [{interestKey:Dogs}, {interestKey:Cats}]}");
List<String> interestList = new ArrayList<String>();
JSONArray jsonArray = jsonObj.getJSONArray("interests");
for(int i = 0 ; i < jsonArray.length() ; i++){
interestList.add(jsonArray.getJSONObject(i).optString("interestKey"));
}
Note : Sometime you may see some exceptions when the values are not available in appropriate type or is there is no mapping key so in those cases when you are not sure about the presence of value so use optString, optInt, optBoolean etc which will simply return the default value if it is not present and even try to convert value to int if it is of string type and vice-versa so Simply No null or NumberFormat exceptions at all in case of missing key or value
From docs
Get an optional string associated with a key. It returns the
defaultValue if there is no such key.
public String optString(String key, String defaultValue) {
String missingKeyValue = json_data.optString("status","N/A");
// note there is no such key as "status" in response
// will return "N/A" if no key found
or To get empty string i.e "" if no key found then simply use
String missingKeyValue = json_data.optString("status");
// will return "" if no key found where "" is an empty string
Further reference to study
Should operator<< be implemented as a friend or as a member function?
Just for completion sake, I would like to add that you indeed can create an operator ostream& operator << (ostream& os) inside a class and it can work. From what I know it's not a good idea to use it, because it's very convoluted and unintuitive.
Let's assume we have this code:
#include <iostream>
#include <string>
using namespace std;
struct Widget
{
string name;
Widget(string _name) : name(_name) {}
ostream& operator << (ostream& os)
{
return os << name;
}
};
int main()
{
Widget w1("w1");
Widget w2("w2");
// These two won't work
{
// Error: operand types are std::ostream << std::ostream
// cout << w1.operator<<(cout) << '\n';
// Error: operand types are std::ostream << Widget
// cout << w1 << '\n';
}
// However these two work
{
w1 << cout << '\n';
// Call to w1.operator<<(cout) returns a reference to ostream&
w2 << w1.operator<<(cout) << '\n';
}
return 0;
}
So to sum it up - you can do it, but you most probably shouldn't :)
FragmentActivity to Fragment
first of all;
a Fragment must be inside a FragmentActivity, that's the first rule,
a FragmentActivity is quite similar to a standart Activity that you already know, besides having some Fragment oriented methods
second thing about Fragments, is that there is one important method you MUST call, wich is onCreateView, where you inflate your layout, think of it as the setContentLayout
here is an example:
@Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { mView = inflater.inflate(R.layout.fragment_layout, container, false); return mView; }
and continu your work based on that mView, so to find a View by id, call mView.findViewById(..);
for the FragmentActivity part:
the xml part "must" have a FrameLayout in order to inflate a fragment in it
<FrameLayout android:id="@+id/content_frame" android:layout_width="match_parent" android:layout_height="match_parent" > </FrameLayout>
as for the inflation part
getSupportFragmentManager().beginTransaction().replace(R.id.content_frame, new YOUR_FRAGMENT, "TAG").commit();
begin with these, as there is tons of other stuf you must know about fragments and fragment activities, start of by reading something about it (like life cycle) at the android developer site
What is the 'pythonic' equivalent to the 'fold' function from functional programming?
Haskell
foldl (+) 0 [1,2,3,4,5]
Python
reduce(lambda a,b: a+b, [1,2,3,4,5], 0)
Obviously, that is a trivial example to illustrate a point. In Python you would just do sum([1,2,3,4,5]) and even Haskell purists would generally prefer sum [1,2,3,4,5].
For non-trivial scenarios when there is no obvious convenience function, the idiomatic pythonic approach is to explicitly write out the for loop and use mutable variable assignment instead of using reduce or a fold.
That is not at all the functional style, but that is the "pythonic" way. Python is not designed for functional purists. See how Python favors exceptions for flow control to see how non-functional idiomatic python is.
How to change the date format from MM/DD/YYYY to YYYY-MM-DD in PL/SQL?
For military time formatting,
select TO_CHAR(SYSDATE, 'yyyy-mm-dd hh24:mm:ss') from DUAL
--2018-07-10 15:07:15
If you want your date to round DOWN to Month, Day, Hour, Minute, you can try
SELECT TO_CHAR( SYSDATE, 'yyyy-mm-dd hh24:mi:ss') "full-date" --2018-07-11 10:40:26
, TO_CHAR( TRUNC(SYSDATE, 'year'), 'yyyy-mm-dd hh24:mi:ss') "trunc-to-year"-- 2018-01-01 00:00:00
, TO_CHAR( TRUNC(SYSDATE, 'month'), 'yyyy-mm-dd hh24:mi:ss') "trunc-to-month" -- 2018-07-01 00:00:00
, TO_CHAR( TRUNC(SYSDATE, 'day'), 'yyyy-mm-dd hh24:mi:ss') "trunc-to-Sunday" -- 2018-07-08 00:00:00
, TO_CHAR( TRUNC(SYSDATE, 'dd'), 'yyyy-mm-dd hh24:mi:ss') "trunc-to-day" -- 2018-07-11 00:00:00
, TO_CHAR( TRUNC(SYSDATE, 'hh'), 'yyyy-mm-dd hh24:mi:ss') "trunc-to-hour" -- 2018-07-11 10:00:00
, TO_CHAR( TRUNC(SYSDATE, 'mi'), 'yyyy-mm-dd hh24:mi:ss') "trunc-to-minute" -- 2018-07-11 10:40:00
from DUAL
For formats literals, you can find help in
https://docs.oracle.com/cd/B28359_01/server.111/b28286/functions242.htm#SQLRF52037
MySql Proccesslist filled with "Sleep" Entries leading to "Too many Connections"?
Before increasing the max_connections variable, you have to check how many non-interactive connection you have by running show processlist command.
If you have many sleep connection, you have to decrease the value of the "wait_timeout" variable to close non-interactive connection after waiting some times.
- To show the wait_timeout value:
SHOW SESSION VARIABLES LIKE 'wait_timeout';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wait_timeout | 28800 |
+---------------+-------+
the value is in second, it means that non-interactive connection still up to 8 hours.
- To change the value of "wait_timeout" variable:
SET session wait_timeout=600;
Query OK, 0 rows affected (0.00 sec)
After 10 minutes if the sleep connection still sleeping the mysql or MariaDB drop that connection.
Change the Right Margin of a View Programmatically?
Use This function to set all Type of margins
public void setViewMargins(Context con, ViewGroup.LayoutParams params,
int left, int top , int right, int bottom, View view) {
final float scale = con.getResources().getDisplayMetrics().density;
// convert the DP into pixel
int pixel_left = (int) (left * scale + 0.5f);
int pixel_top = (int) (top * scale + 0.5f);
int pixel_right = (int) (right * scale + 0.5f);
int pixel_bottom = (int) (bottom * scale + 0.5f);
ViewGroup.MarginLayoutParams s = (ViewGroup.MarginLayoutParams) params;
s.setMargins(pixel_left, pixel_top, pixel_right, pixel_bottom);
view.setLayoutParams(params);
}
