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Is String.Contains() faster than String.IndexOf()?
I have a string buffer of about 2000 characters and need to check the buffer if it contains a specific string.
Will do the check in a ASP.NET 2.0 webapp for every webrequest.
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Fastest way to determine if record exists
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SELECT TOP 1 products.id FROM products WHERE products.id = ?; will outperform all of your suggestions as it will terminate execution after it finds the first record.
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How does a hash table work?
...but strong hashing...
size_t random[8][256] = { ...random data... };
const char* p = (const char*)&my_double;
size_t hash = random[0][(unsigned)p[0]] ^
random[1][(unsigned)p[1]] ^
... ^
random[7][(unsigned)p[7]];
Weak but oft-fast hashing...
Many librar...
What is the difference between “INNER JOIN” and “OUTER JOIN”?
...he intersection of the two tables, i.e. the two rows they have in common.
select * from a INNER JOIN b on a.a = b.b;
select a.*, b.* from a,b where a.a = b.b;
a | b
--+--
3 | 3
4 | 4
Left outer join
A left outer join will give all rows in A, plus any common rows in B.
select * from a LEFT OUT...
How to check if command line tools is installed
...ars in the Applications directory.
There are also the xcodebuild and xcode-select files in /usr/bin
I need to know if the command line tools is installed.
Is there a command for it?
What can I do to see if XCode CLT is installed and if yes to find the version installed?
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Select data from date range between two dates
...uch more simple (only two cases against four).
Your SQL will look like:
SELECT * FROM Product_sales
WHERE NOT (From_date > @RangeTill OR To_date < @RangeFrom)
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How do I run a batch file from my Java Application?
... int i = 0;
while( (i = is.read() ) != -1) {
System.out.print((char)i);
}
} catch(IOException ioException) {
System.out.println(ioException.getMessage() );
}
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Simplest way to do a recursive self-join?
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WITH q AS
(
SELECT *
FROM mytable
WHERE ParentID IS NULL -- this condition defines the ultimate ancestors in your chain, change it as appropriate
UNION ALL
SELECT m.*
FROM mytable m
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SQL Server CTE and recursion example
...The query finds all root nodes as described by WHERE ManagerID IS NULL
SELECT EmployeeID, FirstName, LastName, ManagerID, 1
FROM Employees
WHERE ManagerID IS NULL
-->>>>>>>>>>Block 1>>>>>>>>>>>>>>>>>
UNI...
Can you have if-then-else logic in SQL? [duplicate]
I need to do select data from a table based on some kind of priority like so:
7 Answers
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