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MySQL: @variable vs. variable. What's the difference?
...are loosely typed variables that may be initialized somewhere in a session and keep their value until the session ends.
They are prepended with an @ sign, like this: @var
You can initialize this variable with a SET statement or inside a query:
SET @var = 1
SELECT @var2 := 2
When you develop a stor...
What are the options for storing hierarchical data in a relational database? [closed]
...in this thread suggested. Use an Adjacency List to maintain the hierarchy and use Nested Sets to query the hierarchy.
The problem up until now has been that the coversion method from an Adjacecy List to Nested Sets has been frightfully slow because most people use the extreme RBAR method known as ...
Why do people put code like “throw 1; ” and “for(;;);” in front of json responses? [du
...ased on altering the behaviour of the built-in types, in particular Object and Array, by altering their constructor function or its prototype. Then when the targeted JSON uses a {...} or [...] construct, they'll be the attacker's own versions of those objects, with potentially-unexpected behaviour.
...
CSS center text (horizontally and vertically) inside a div block
I have a div set to display:block ( 90px height and width ), and I have some text inside.
27 Answers
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Use of *args and **kwargs [duplicate]
So I have difficulty with the concept of *args and **kwargs .
11 Answers
11
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Getting the last element of a list
...
some_list[-1] is the shortest and most Pythonic.
In fact, you can do much more with this syntax. The some_list[-n] syntax gets the nth-to-last element. So some_list[-1] gets the last element, some_list[-2] gets the second to last, etc, all the way down t...
Where can I locate themes for VS2012
...soft.com/366ad100-0003-4c9a-81a8-337d4e7ace05
Comes w/ VS 2010 style blue and a few others...
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How to convert byte array to string and vice versa?
I have to convert a byte array to string in Android, but my byte array contains negative values.
22 Answers
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What is the difference between _tmain() and main() in C++?
...n does.
_tmain is a Microsoft extension.
main is, according to the C++ standard, the program's entry point.
It has one of these two signatures:
int main();
int main(int argc, char* argv[]);
Microsoft has added a wmain which replaces the second signature with this:
int wmain(int argc, wchar_t* ...
Understanding dict.copy() - shallow or deep?
... 3, 4, 5]}, {1: [1, 2, 3, 4]})
So:
b = a: Reference assignment, Make a and b points to the same object.
b = a.copy(): Shallow copying, a and b will become two isolated objects, but their contents still share the same reference
b = copy.deepcopy(a): Deep copying, a and b's structure and conte...