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How do write IF ELSE statement in a MySQL query
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150
You probably want to use a CASE expression.
They look like this:
SELECT col1, col2, (case when...
Peak memory usage of a linux/unix process
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20 Answers
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What does the constant 0.0039215689 represent?
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0.0039215689 is approximately equal to 1/255.
Seeing that this is OpenGL, performance is probably important. So it's probably safe to guess that this was done for performance reasons.
Multiplying by the reciprocal is faster...
How to check whether a pandas DataFrame is empty?
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505
You can use the attribute df.empty to check whether it's empty or not:
if df.empty:
print(...
Putting text in top left corner of matplotlib plot
...t is in data coords,
alternatively, you can specify text in axis coords (0,0 is lower-left
and 1,1 is upper-right). The example below places text in the center
of the axes::
text(0.5, 0.5,'matplotlib',
horizontalalignment='center',
verticalalignment='center',
transform = ax.t...
Index all *except* one item in python
.... For example, to make b a copy of a without the 3rd element:
a = range(10)[::-1] # [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
b = [x for i,x in enumerate(a) if i!=3] # [9, 8, 7, 5, 4, 3, 2, 1, 0]
This is very general, and can be used with all iterables, including numpy arrays. If y...
Best way to combine two or more byte arrays in C#
...he suggested methods in a loop executed 1 million times using 3 arrays of 10 bytes each. Here are the results:
New Byte Array using System.Array.Copy - 0.2187556 seconds
New Byte Array using System.Buffer.BlockCopy - 0.1406286 seconds
IEnumerable<byte> using C# yield operator - 0....
Tools for analyzing performance of a Haskell program
...oblem.
Run your program with +RTS -s
$ time ./A +RTS -s
./A +RTS -s
749700
9,961,432,992 bytes allocated in the heap
2,463,072 bytes copied during GC
29,200 bytes maximum residency (1 sample(s))
187,336 bytes maximum slop
**2 MB** total memory in use (0...
How can I perform a culture-sensitive “starts-with” operation from the middle of a string?
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+100
I'll consider the problem of many<->one/many casemappings first and separately from handling different Normalization forms.
Fo...
Why is (object)0 == (object)0 different from ((object)0).Equals((object)0)?
...Int32.Equals and this checks for a boxed integer. Both integer values are 0 hence they are equal
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