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Swapping column values in MySQL
...t. This method doesn't swap the values if one of them is NULL. Use method #3 that doesn't have this limitation.
UPDATE swap_test SET x=y, y=@temp WHERE (@temp:=x) IS NOT NULL;
This method was offered by Dipin in, yet again, the comments of http://beerpla.net/2009/02/17/swapping-column-values-in-mys...
Group by & count function in sqlalchemy
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3 Answers
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Reload django object from database
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Tim FletcherTim Fletcher
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Will using goto leak variables?
...();
lol:
return 0;
}
// error: label 'lol' used but not defined
[n3290: 6.1/1]: [..] The scope of a label is the function in which
it appears. [..]
2. Object initialisation
You can't jump across object initialisation:
int main() {
goto lol;
int x = 0;
lol:
return 0;
}
// e...
Rails migrations: self.up and self.down versus change
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3 Answers
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Set “this” variable easily?
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223
There are two methods defined for all functions in JavaScript, call(), and apply(). The function...
How do I print the elements of a C++ vector in GDB?
...ctor
This will produce an output similar to:
$1 = std::vector of length 3, capacity 4 = {10, 20, 30}
To achieve above, you need to have gdb 7 (I tested it on gdb 7.01) and some python pretty-printer. Installation process of these is described on gdb wiki.
What is more, after installing above, ...
How can I show the name of branches in `git log`?
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Select second last element with css
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In CSS3 you have:
:nth-last-child(2)
See: https://developer.mozilla.org/en-US/docs/Web/CSS/:nth-last-child
nth-last-child Browser Support:
Chrome 2
Firefox 3.5
Opera 9.5, 10
Safari 3.1, 4
Internet Explorer 9
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