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Difference between EXISTS and IN in SQL?
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The exists keyword can be used in that way, but really it's intended as a way to avoid counting:
--this statement needs to check the entire table
select count(*) from [table] where ...
--this statement is true as soon as one match is found
exists ( select * from [table] ...
Why do people write the #!/usr/bin/env python shebang on the first line of a Python script?
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If you have several versions of Python installed, /usr/bin/env will ensure the interpreter used is the first one on your environment's $PATH. The alternative would be to hardcode something like #!/usr/bin/python; that's ok, but less flexible.
In Unix, an executable f...
ThreadStatic v.s. ThreadLocal: is generic better than attribute?
...low is the simple demonstration:
public static ThreadLocal<int> _threadlocal =
new ThreadLocal<int>(() =>
{
return Thread.CurrentThread.ManagedThreadId;
});
public static void Main()
{
new Thread(() =>
{
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Update multiple columns in SQL
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i think use 1keydata.com/sql/sqlupdate.html "SET column_1 = [value1], column_2 = [value2]"
– DeLe
Jun 9 '13 at 1:01
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Mix Razor and Javascript code
...avascript blocks when executed but I hate how the syntax highlighting gets all sorts of confused. It highlights all the Razor code as invalid Syntax because it's stuck in Javascript mode I believe.
– Chev
Aug 10 '12 at 16:29
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Is there a .NET/C# wrapper for SQLite? [closed]
...is the original SQLite database engine and a complete ADO.NET 2.0 provider all rolled into a single mixed mode assembly. It is a complete drop-in replacement for the original sqlite3.dll (you can even rename it to sqlite3.dll). Unlike normal mixed assemblies, it has no linker dependency on the .NE...
How to sort my paws?
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Alright! I've finally managed to get something working consistently! This problem pulled me in for several days... Fun stuff! Sorry for the length of this answer, but I need to elaborate a bit on some things... (Though I may set a record for ...
Website screenshots
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Sure you can, but you'll need to render the page with something.
If you really want to only use php, I suggest you HTMLTOPS, which renders the page and outputs it in a ps file (ghostscript), then, convert it in a .jpg, .png, .pdf.. can be little slower with complex pages (and don't support all the ...
Fastest check if row exists in PostgreSQL
...f a single row from the batch exists in the table because then I know they all were inserted.
8 Answers
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Eclipse/Java code completion not working
...o previously suffering from Eclipse thinking my project was in 1.5 despite all options saying otherwise, so it must have been corrupted during this issue.
– Philip Guin
Jun 30 '13 at 6:51
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