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Difference between Key, Primary Key, Unique Key and Index in MySQL
...would use indexes to improve the speed of data retrieval. An index is typically created on columns used in JOIN, WHERE, and ORDER BY clauses.
Imagine you have a table called users and you want to search for all the users which have the last name 'Smith'. Without an index, the database would have t...
How to impose maxlength on textArea in HTML using JavaScript
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@JoshStodola - Indeed you cannot. It would really annoy me as a user if I had pasted a whole piece of something in a textarea, clicked submit, and only saw a small portion of it go through without any response.
– Travis J
Apr 30 '1...
PATH issue with pytest 'ImportError: No module named YadaYadaYada'
I used easy_install to install pytest on a mac and started writing tests for a project with a file structure likes so:
20 A...
moving changed files to another branch for check-in
... you have not made the commit yet, just run git stash. This will save away all of your changes.
Switch to the branch you want the changes on and run git stash pop.
There are lots of uses for git stash. This is certainly one of the more useful reasons.
An example:
# work on some code
git stash
gi...
What is the difference between Polymer elements and AngularJS directives?
...js is a library that contains several polyfills for various W3C APIs that fall under the Web Components umbrella. These are:
Custom Elements
HTML Imports
<template>
Shadow DOM
Pointer Events
others
The left-nav in the documentation (polymer-project.org) has a page for all of these "Platfor...
isset() and empty() - what to use
... check - is variable empty or contains something. To solve this task, I usually do the following.
6 Answers
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What is the most frequent concurrency issue you've encountered in Java? [closed]
...are not synchronized this is not guaranteed to work. This mistake is especially devilish as in 99.999% it won't matter in practice as the reader thread will eventually see the change - but we don't know how soon he saw it.
s...
Use of .apply() with 'new' operator. Is this possible?
...CMAScript5's Function.prototype.bind things get pretty clean:
function newCall(Cls) {
return new (Function.prototype.bind.apply(Cls, arguments));
// or even
// return new (Cls.bind.apply(Cls, arguments));
// if you know that Cls.bind has not been overwritten
}
It can be used as foll...
How do I measure request and response times at once using cURL?
...me="curl -w \"@$HOME/.curl-format.txt\" -o NUL -s "
Then you can simply call...
curltime wordpress.org
Thanks to commenter Pete Doyle!
Make a Linux/Mac stand-alone script
This script does not require a separate .txt file to contain the formatting.
Create a new file, curltime, somewhere in ...
Django, creating a custom 500/404 error page
... for some reason request.user appears fine in the 404 template, but not at all in the 500 template (and they are almost identical) -- posted question on this here: stackoverflow.com/questions/26043211/…
– Gravity Grave
Sep 25 '14 at 16:13
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