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What is the difference between JOIN and UNION?
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UNION puts lines from queries after each other, while JOIN makes a cartesian product and subsets it -- completely different operations. Trivial example of UNION:
mysql> SELECT 23 AS bah
-> UNION
-> SELECT 45 AS bah;
+-----+
| bah |
+-----+
| 23 |
| 45 |
+-----+
2 ...
How to initialize a dict with keys from a list and empty value in Python?
I'd like to get from this:
6 Answers
6
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Get first n characters of a string
...tring = substr($string,0,10).'...';
Update:
Based on suggestion for checking length (and also ensuring similar lengths on trimmed and untrimmed strings):
$string = (strlen($string) > 13) ? substr($string,0,10).'...' : $string;
So you will get a string of max 13 characters; either 13 (or les...
OpenSSL and error in reading openssl.conf file
... from the commandline you can type:
set OPENSSL_CONF=c:/libs/openssl-0.9.8k/openssl.cnf
to validate it you can type:
echo %OPENSSL_CONF%
You can also set it as part of the computer's environmental variables so all users and services have it available by default. See, for example, Environment v...
What is href=“#” and why is it used?
On many websites I see links that have href="#" . What does it mean? What is it used for?
9 Answers
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What does !important mean in CSS?
...ave priority.
Using !important has its purposes (though I struggle to think of them), but it's much like using a nuclear explosion to stop the foxes killing your chickens; yes, the foxes will be killed, but so will the chickens. And the neighbourhood.
It also makes debugging your CSS a nightmare (...
How do I change the working directory in Python?
cd is the shell command to change the working directory.
14 Answers
14
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The 'json' native gem requires installed build tools
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I believe those installers make changes to the path. Did you try closing and re-opening the CMD window after running them and before the last attempt to install the gem that wants devkit present?
Also, be sure you are using the right devkit installer ...
If my interface must return Task what is the best way to have a no-operation implementation?
...the code below, due to the interface, the class LazyBar must return a task from its method (and for argument's sake can't be changed). If LazyBar s implementation is unusual in that it happens to run quickly and synchronously - what is the best way to return a No-Operation task from the method?
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disable nganimate for some elements
...this to your CSS. It is best if it is the last rule:
.no-animate {
-webkit-transition: none !important;
transition: none !important;
}
then add no-animate to the class of element you want to disable. Example:
<div class="no-animate"></div>
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