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Is there an auto increment in sqlite?
... In case it is not obvious from answer, you can use ROWID in your select statement e.g. select rowid from people;
– Colin D
Mar 20 '17 at 15:37
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How do I remove all non alphanumeric characters from a string except dash?
How do I remove all non alphanumeric characters from a string except dash and space characters?
13 Answers
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Turn a string into a valid filename?
I have a string that I want to use as a filename, so I want to remove all characters that wouldn't be allowed in filenames, using Python.
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Xcode 4 - “Archive” is greyed out?
...
You have to select the device in the schemes menu in the top left where you used to select between simulator/device. It won’t let you archive a build for the simulator.
Or you may find that if the iOS device is already selected the ar...
Implicit type conversion rules in C++ operators
...re promoted to int
Note. The minimum size of operations is int. So short/char are promoted to int before the operation is done.
In all your expressions the int is promoted to a float before the operation is performed. The result of the operation is a float.
int + float => float + float = flo...
Base64 length calculation?
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Each character is used to represent 6 bits (log2(64) = 6).
Therefore 4 chars are used to represent 4 * 6 = 24 bits = 3 bytes.
So you need 4*(n/3) chars to represent n bytes, and this needs to be rounded up to a multiple of 4.
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Get first n characters of a string
How can I get the first n characters of a string in PHP? What's the fastest way to trim a string to a specific number of characters, and append '...' if needed?
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__attribute__ - C/C++ - 清泛网 - 专注C/C++及内核技术
...数,其功能类似于printf:
//m=1;n=2
extern void myprint(const char *format,...) __attribute__((format(printf,1,2)));
//m=2;n=3
extern void myprint(int l,const char *format,...)
__attribute__((format(printf,2,3)));
需要特别注意的是,如果myprint是一个函数的成员...
How to truncate string using SQL server
...ou only want to return a few characters of your long string, you can use:
select
left(col, 15) + '...' col
from yourtable
See SQL Fiddle with Demo.
This will return the first 15 characters of the string and then concatenates the ... to the end of it.
If you want to to make sure than strings ...
How do I duplicate a whole line in Emacs?
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which breaks down to
C-a: move cursor to start of line
C-SPACE: begin a selection ("set mark")
C-n: move cursor to next line
M-w: copy region
C-y: paste ("yank")
The aforementioned
C-a C-k C-k C-y C-y
amounts to the same thing (TMTOWTDI)
C-a: move cursor to start of line
C-k: cut ("kill") ...