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How do I check if an index exists on a table field in MySQL?
...re a.table_schema = 'your_schema'
and a.column_name = 'your_column'
order by a.table_schema, a.table_name;
since the joins are against INNODB_SYS_*, so the match indexes only came from INNODB tables only
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Scala downwards or decreasing for loop?
In Scala, you often use an iterator to do a for loop in an increasing order like:
7 Answers
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Can you have if-then-else logic in SQL? [duplicate]
... in dbs it is not optimal because this syntax is procedural - it would be orders of magnitude slower than a proper set based query.
– mson
Feb 28 '13 at 13:42
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Check if an image is loaded (no errors) with jQuery
...pt with the jQuery library to manipulate image thumbnails contained in a unordered list. When the image is loaded it does one thing, when an error occurs it does something else. I'm using jQuery load() and error() methods as events. After these events I check the image DOM element for the .comp...
How to properly seed random number generator
... That will return all the time the very same sequence, in the very same order if called multiple times, that does not look very random to me. Check live example: play.golang.org/p/fHHENtaPv5 3 5 2 5 4 2 5 6 3 1
– Thomas Modeneis
Oct 6 '16 at 13:05
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How to log cron jobs?
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* * * * * myjob.sh >> /var/log/myjob.log 2>&1
will log all output from the cron job to /var/log/myjob.log
You might use mail to send emails. Most systems will send unhandled cron job output by email to root or the corresponding user.
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When should I make explicit use of the `this` pointer?
...w to treat i, since it may or may not exist in all instantiations of A. In order to tell it that i is indeed a member of A<T>, for any T, the this-> prefix is required.
Note: it is possible to still omit this-> prefix by using:
template<class T>
struct B : A<T> {
using...
MySQL show current connection info
... Or you could use Yousui's answer of mysql> status, which returns all of this in a single command.
– a coder
Jul 23 '14 at 20:20
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Unable to understand useCapture parameter in addEventListener
...g ("capture"), and at the end ("bubble").
Events are executed in the order of how they're defined. Say, you define 4 event listeners:
window.addEventListener("click", function(){console.log(1)}, false);
window.addEventListener("click", function(){console.log(2)}, true);
window.addEventL...
In Java, how do I check if a string contains a substring (ignoring case)? [duplicate]
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