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MySQL, better to insert NULL or empty string?
...a lot of different fields. Some of the fields are optional while some are mandatory. In my DB I have a table which holds all these values, is it better practice to insert a NULL value or an empty string into the DB columns where the user didn't put any data?
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must appear in the GROUP BY clause or be used in an aggregate function
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To workaround this issue, you must calculate the aggregate in a sub-query and then join it with itself to get the additional columns you'd need to show:
SELECT m.cname, m.wmname, t.mx
FROM (
SELECT cname, MAX(avg) AS mx
FROM makerar
GROUP BY cname
) t JOIN makerar m ON m.cname = t....
Should I use int or Int32
In C#, int and Int32 are the same thing, but I've read a number of times that int is preferred over Int32 with no reason given. Is there a reason, and should I care?
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Default parameters with C++ constructors [closed]
...efault parameters, so long as the parameters make sense. Classes in the standard use them as well, which speaks in their favor.
One thing to watch out for is if you have defaults for all but one parameter, your class can be implicitly converted from that parameter type. Check out this thread for ...
What is the best way to tell if a character is a letter or number in Java without using regexes?
What is the best and/or easiest way to recognize if a string.charAt(index) is an A-z letter or a number in Java without using regular expressions? Thanks.
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how to make a whole row in a table clickable as a link?
I'm using Bootstrap and the following doesn't work:
26 Answers
26
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How to determine height of UICollectionView with FlowLayout
I've got an UICollectionView with an UICollectionViewFlowLayout , and i want to calculate its content size (for return in intrinsicContentSize needed for adjusting its height via AutoLayout).
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C# 'is' operator performance
... answered Mar 26 '09 at 16:09
Andrew HareAndrew Hare
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virtualenvwrapper and Python 3
I installed python 3.3.1 on ubuntu lucid and successfully created a virtualenv as below
9 Answers
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How can I use numpy.correlate to do autocorrelation?
I need to do auto-correlation of a set of numbers, which as I understand it is just the correlation of the set with itself.
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