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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 ...
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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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.
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Unpacking, extended unpacking and nested extended unpacking
...lain with a few examples. Since you're talking about evaluating these "by hand," I'll suggest some simple substitution rules. Basically, you might find it easier to understand an expression if all the iterables are formatted in the same way.
For the purposes of unpacking only, the following substit...
How are the points in CSS specificity calculated
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Pekka's answer is practically correct, and probably the best way to think about the issue.
However, as many have already pointed out, the W3C CSS recommendation states that "Concatenating the three numbers a-b-c (in a number system with a large base) gives the sp...
The located assembly's manifest definition does not match the assembly reference
...un some unit tests in a C# Windows Forms application (Visual Studio 2005), and I get the following error:
53 Answers
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How to search by key=>value in a multidimensional array in PHP
..._r takes its fourth parameter by reference rather than by value; the ampersand & is crucial.
FYI: If you have an older version of PHP then you have to specify the pass-by-reference part in the call to search_r rather than in its declaration. That is, the last line becomes search_r($subarray, $k...
Use of *args and **kwargs [duplicate]
So I have difficulty with the concept of *args and **kwargs .
11 Answers
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How to request Administrator access inside a batch file
....bat file. The desired behavior is that when they right-click on the file and say Open, they will get one of those UAC dialogs that makes the screen go dark and forces them to answer whether they want to give the application permission to run as administrator. Instead, they are just seeing "Access...
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...