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PostgreSQL Crosstab Query
... | 4 | 5
C | 7 | -- !!
No need for casting and renaming.
Note the incorrect result for C: the value 7 is filled in for the first column. Sometimes, this behavior is desirable, but not for this use case.
The simple form is also limited to exactly three columns ...
Why do I get a segmentation fault when writing to a “char *s” initialized with a string literal, but
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Whenever using "%p" on printf, you should cast the pointer to void * as in printf("%p", (void *)str); When printing a size_t with printf, you should use "%zu" if using the latest C standard (C99).
– Chris Young
Oct 3 '08 at 7:44...
What's the difference(s) between .ToList(), .AsEnumerable(), AsQueryable()?
...st() along the way.
What do these methods do?
AsEnumerable and AsQueryable cast or convert to IEnumerable or IQueryable, respectively. I say cast or convert with a reason:
When the source object already implements the target interface, the source object itself is returned but cast to the target int...
Is it possible to capture a Ctrl+C signal and run a cleanup function, in a “defer” fashion?
I want to capture the Ctrl+C ( SIGINT ) signal sent from the console and print out some partial run totals.
10 Answers
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Does the Java &= operator apply & or &&?
...So a &= b; is equivalent to a = a & b;.
(In some usages, the type-casting makes a difference to the result, but in this one b has to be boolean and the type-cast does nothing.)
And, for the record, a &&= b; is not valid Java. There is no &&= operator.
In practice, there...
How do I check if a SQL Server text column is empty?
...he added overhead of calling SQL Functions like DataLength(), IsNull(), or Cast(). Maybe the generated query plan is the same (I didn't check); still I find this to be a far cleaner approach.
– MikeTeeVee
Nov 13 '19 at 11:49
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Python: Get relative path from comparing two absolute paths
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os.path.commonprefix() and os.path.relpath() are your friends:
>>> print os.path.commonprefix(['/usr/var/log', '/usr/var/security'])
'/usr/var'
>>> print os.path.commonprefix(['/tmp', '/usr/var']) # No common prefix: the root is...
How can I check a C# variable is an empty string “” or null? [duplicate]
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Are we to assume that this conversion of stringVar to a cast object returns empty string for both null and empty string assigned to the stringVar variable, but converting the same stringVar without the cast returns null and empty string instead? Im just trying to find out all the ...
Redirect stdout to a file in Python?
... common method is to use shell redirection when executing (same on Windows and Linux):
$ python foo.py > file
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How to find if directory exists in Python
...en classes are callable. Also, functions are first-class values in Python, and you can use them without the parentheses notation, like in existing = filter(os.path.isdir(['/lib', '/usr/lib', '/usr/local/lib'])
– phihag
Mar 30 '13 at 7:38
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