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Counting DISTINCT over multiple columns
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If you are trying to improve performance, you could try creating a persisted computed column on either a hash or concatenated value of the two columns.
Once it is persisted, provided the column is deterministic and you are using "sane" database settings, ...
JQuery .on() method with multiple event handlers to one selector
... one handler per <td> element becomes mandatory to achieve usable performance.
– Frédéric Hamidi
Aug 17 '12 at 19:10
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E11000 duplicate key error index in mongodb mongoose
...u already have a user without an email address.
The relevant documentation for this:
If a document does not have a value for the indexed field in a unique index, the index will store a null value for this document. Because of the unique constraint, MongoDB will only permit one document that lacks t...
Preventing form resubmission
Page one contains an HTML form. Page two - the code that handles the submitted data.
12 Answers
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JavaScript displaying a float to 2 decimal places
...ur target number converted to a nice string with X digits then convert the formated string to a number.
Number( (myVar).toFixed(2) )
See example below:
var myNumber = 5.01;
var multiplier = 5;
$('#actionButton').on('click', function() {
$('#message').text( myNumber * multiplier );
});...
How do I get the height and width of the Android Navigation Bar programmatically?
...movable in Android. It has been part of Android since 3.0 as a replacement for hardware buttons. Here is a picture:
18 Answ...
PHP ORMs: Doctrine vs. Propel
...ndering if more experienced people out there have general pros and/or cons for going with either of these two?
10 Answers
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Renew Provisioning Profile
Just got a notice that the provisioning profile for one of my apps is about to expire. Is there some way I can renew the existing one or must I recreate a new one?
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How to quit android application programmatically
I Found some codes for quit an Android application programatically. By calling any one of the following code in onDestroy() will it quit application entirely?
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Diagnosing Memory Leaks - Allowed memory size of # bytes exhausted
I've encountered the dreaded error-message, possibly through-painstaking effort, PHP has run out of memory:
13 Answers
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