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PostgreSQL Crosstab Query
Does any one know how to create crosstab queries in PostgreSQL?
For example I have the following table:
6 Answers
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How to resize a VirtualBox vmdk file
...e the UUID automatically. I had to remove the hard drive from the list of known hard drives (File -> Virtual Media Manager) and then re-add it to the instance.
– Chaim Eliyah
Dec 14 '17 at 22:14
...
Checkbox for nullable boolean
...rty:
public class MyViewModel
{
public bool Foo { get; set; }
}
and now you will have your controller action pass this view model to the view and generate the proper checkbox.
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SQL SELECT WHERE field contains words
...LIKE '%word1%'
OR column1 LIKE '%word2%'
OR column1 LIKE '%word3%'
If you need all words to be present, use this:
SELECT * FROM mytable
WHERE column1 LIKE '%word1%'
AND column1 LIKE '%word2%'
AND column1 LIKE '%word3%'
If you want something faster, you need to look into full text sear...
How to use “raise” keyword in Python [duplicate]
.... If e was a TypeError or ValueError or LibrarySpecificException you can't now catch those specific exceptions anymore, because you replaced it with Exception.
– Martijn Pieters♦
Apr 29 at 11:39
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How to print to console in pytest?
...es the result of standard out so that it can control how it prints it out. If it didn't do this, it would spew out a lot of text without the context of what test printed that text.
However, if a test fails, it will include a section in the resulting report that shows what was printed to standard ou...
Is returning by rvalue reference more efficient?
...e following
Beta_ab
Beta::toAB() const {
return Beta_ab(1, 1);
}
Now, it's properly moving a temporary Beta_ab object into the return value of the function. If the compiler can, it will avoid the move altogether, by using RVO (return value optimization). Now, you can do the following
Beta...
Why can templates only be implemented in the header file?
...compiled.
So when foo.cpp is compiled, the compiler can't see bar.cpp to know that MyClass<int> is needed. It can see the template MyClass<T>, but it can't emit code for that (it's a template, not a class). And when bar.cpp is compiled, the compiler can see that it needs to create a MyC...
When to use Comparable and Comparator
...
I would say that an object should implement Comparable if that is the clear natural way to sort the class, and anyone would need to sort the class would generally want to do it that way.
If, however, the sorting was an unusual use of the class, or the sorting only makes sense fo...
Can a decorator of an instance method access the class?
...
If you are using Python 2.6 or later you could use a class decorator, perhaps something like this (warning: untested code).
def class_decorator(cls):
for name, method in cls.__dict__.iteritems():
if hasattr(method...