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How do I query if a database schema exists
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Just to be extra "defensive", the following version generates a Type conversion error to account for the possibility (however unlikely) of > 1 matching Schema's similar to how validation code often intentionally Throw Exception's bec...
How do I create a random alpha-numeric string in C++?
I'd like to create a random string, consisting of alpha-numeric characters. I want to be able to be specify the length of the string.
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Command to change the default home directory of a user
...ou can also use bind-mount:
mkdir /home/username
mount --bind --verbose /extra-home/username /home/username
This is useful for allowing access "through" the /home directory to subdirs via daemons that are otherwise configured to avoid pathing through symlinks (apache, ftpd, etc.).
You have to r...
Preferred method to store PHP arrays (json_encode vs serialize)
...2.180496931076 seconds
JSON decoded in 9.8368630409241 seconds
serialized "String" size : 13993
Native PHP :
PHP serialized in 2.9125759601593 seconds
PHP unserialized in 6.4348418712616 seconds
serialized "String" size : 20769
Igbinary :
WIN igbinary serialized in 1.6099879741669 secon...
Creating C macro with ## and __LINE__ (token concatenation with positioning macro)
...the token-pasting operator ## are applied to it. So, you have to use some extra layers of indirection, you can use the token-pasting operator with a recursively expanded argument:
#define TOKENPASTE(x, y) x ## y
#define TOKENPASTE2(x, y) TOKENPASTE(x, y)
#define UNIQUE static void TOKENPASTE2(Uniq...
HTML+CSS: How to force div contents to stay in one line?
...ple of things here, you need overflow: hidden if you don't want to see the extra characters poking out into your layout.
Also, as mentioned, you could use white-space: pre (see EnderMB) keeping in mind that pre will not collapse white space whereas white-space: nowrap will.
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Why does base64 encoding require padding if the input length is not divisible by 3?
...d sequence.
However, padding is useful in situations where base64 encoded strings are concatenated in such a way that the lengths of the individual sequences are lost, as might happen, for example, in a very simple network protocol.
If unpadded strings are concatenated, it's impossible to recover...
What's faster, SELECT DISTINCT or GROUP BY in MySQL?
... even a DISTINCT+ORDER BY might still be faster than a GROUP BY due to the extra hints for the optimizer as explained by SquareCog.
– rustyx
Jan 25 '15 at 15:03
1
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Get only part of an Array in Java?
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there is another problem. What if I need to split the string array of length say 500K into the subarrays of 250K. These method accepts interegr which max out at 65000.
– Vishnu Dahatonde
Oct 10 '17 at 10:20
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What does -D_XOPEN_SOURCE do/mean?
...t;some number>
it tells your compiler to include definitions for some extra functions that are defined in the X/Open and POSIX standards.
This will give you some extra functionality that exists on most recent UNIX/BSD/Linux systems, but probably doesn't exist on other systems such as Windows.
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