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SQL UPDATE SET one column to be equal to a value in a related table referenced by a different column
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Without the update-and-join notation (not all DBMS support that), use:
UPDATE QuestionTrackings
SET QuestionID = (SELECT QuestionID
FROM AnswerTrackings
WHERE AnswerTrackings.AnswerID = QuestionTrackings.AnswerID)
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Find the most common element in a list
...roups by the item only (via operator.itemgetter). The auxiliary function, called once per grouping during the max computation, receives and internally unpacks a group - a tuple with two items (item, iterable) where the iterable's items are also two-item tuples, (item, original index) [[the items of ...
Advantages to Using Private Static Methods
When creating a class that has internal private methods, usually to reduce code duplication, that don't require the use of any instance fields, are there performance or memory advantages to declaring the method as static?
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`if __name__ == '__main__'` equivalent in Ruby
...f there isn't really a good, clean way of doing this.
EDIT: Found it.
if __FILE__ == $0
foo()
bar()
end
But it's definitely not common.
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Why am I getting a “401 Unauthorized” error in Maven?
...publish.
The SNAPSHOTS repository (as opposed to the releases repository) allows you to overwrite a similarly numbered version, but your version number should have "-SNAPSHOT" at the end of it.
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How to get the caller's method name in the called method?
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This seems to work just fine:
import sys
print sys._getframe().f_back.f_code.co_name
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How to get the concrete class name as a string? [duplicate]
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instance.__class__.__name__
example:
>>> class A():
pass
>>> a = A()
>>> a.__class__.__name__
'A'
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Python's json module, converts int dictionary keys to strings
...which implement a __hash__ method. (The Lua docs suggest that it automatically uses the object's ID as a hash/key even for mutable objects and relies on string interning to ensure that equivalent strings map to the same objects).
In Perl, Javascript, awk and many other languages the keys for hash...
Unmangling the result of std::type_info::name
... calling function. This should be relatively easy, standard C++ has a type_info class. This contains the name of the typeid'd class/function/etc. but it's mangled. It's not very useful. I.e. typeid(std::vector<int>).name() returns St6vectorIiSaIiEE .
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How to check 'undefined' value in jQuery
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JQuery library was developed specifically to simplify and to unify certain JavaScript functionality.
However if you need to check a variable against undefined value, there is no need to invent any special method, since JavaScript has a typeof operator, which is...