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What is the most efficient/elegant way to parse a flat table into a tree?
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Now that MySQL 8.0 supports recursive queries, we can say that all popular SQL databases support recursive queries in standard syntax.
WITH RECURSIVE MyTree AS (
SELECT * FROM MyTable WHERE ParentId IS NULL
UNION ALL
SELECT m.* F...
How to check if a process id (PID) exists
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10 Answers
10
Active
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Java: how can I split an ArrayList in multiple small ArrayLists?
How can I split an ArrayList (size=1000) in multiple ArrayLists of the same size (=10) ?
18 Answers
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Remove border from IFrame
... capital ‘B’).
So it would look like:
<iframe src="myURL" width="300" height="300" frameBorder="0">Browser not compatible.</iframe>
share
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improve this answer
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How to find the sum of an array of numbers
... how can I find the sum of its elements? (In this case, the sum would be 10 .)
43 Answers
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How to reliably open a file in the same directory as a Python script
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203
I always use:
__location__ = os.path.realpath(
os.path.join(os.getcwd(), os.path.dirname(__...
Returning value from called function in a shell script
... echo >&2 "successfully acquired lock: $lockdir"
retval=0
else
echo >&2 "cannot acquire lock, giving up on $lockdir"
retval=1
fi
return "$retval"
}
testlock
retval=$?
if [ "$retval" == 0 ]
then
echo "directory not created"
else
echo ...
jquery if div id has children
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if ( $('#myfav').children().length > 0 ) {
// do something
}
This should work. The children() function returns a JQuery object that contains the children. So you just need to check the size and see if it has at least one child.
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Fill SVG path element with a background-image
...<defs>
<pattern id="img1" patternUnits="userSpaceOnUse" width="100" height="100">
<image href="wall.jpg" x="0" y="0" width="100" height="100" />
</pattern>
</defs>
Adjust the width and height according to your image, then reference it from the path like this:
&...
Standard deviation of a list
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Since Python 3.4 / PEP450 there is a statistics module in the standard library, which has a method stdev for calculating the standard deviation of iterables like yours:
>>> A_rank = [0.8, 0.4, 1.2, 3.7, 2.6, 5.8]
>>> import statis...