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LINQ: When to use SingleOrDefault vs. FirstOrDefault() with filtering criteria
... When I ran a SingleOrDefault through LinqPad and VS, I never got SELECT TOP 2, with FirstOrDefault I was able to get SELECT TOP 1, but as far as I can tell you do not get SELECT TOP 2.
– Jamie R Rytlewski
Dec 22 '11 at 15:04
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How to pass an array into a SQL Server stored procedure
...WithEmployees
@List AS dbo.IDList READONLY
AS
BEGIN
SET NOCOUNT ON;
SELECT ID FROM @List;
END
GO
Now in your C# code:
// Obtain your list of ids to send, this is just an example call to a helper utility function
int[] employeeIds = GetEmployeeIds();
DataTable tvp = new DataTable();
tvp.C...
Locate current file in IntelliJ
...ecause you followed a reference to java.io.File.
The keymap defines it as Select current file or symbol in any view.
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SQL Query Where Field DOES NOT Contain $x
...t is meant to be used in subqueries or with predefined lists:
-- subquery
SELECT a FROM x WHERE x.b NOT IN (SELECT b FROM y);
-- predefined list
SELECT a FROM x WHERE x.b NOT IN (1, 2, 3, 6);
If you are searching a string, go for the LIKE operator (but this will be slow):
-- Finds all rows where...
(![]+[])[+[]]… Explain why this works
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As @Mauricio commented (![]+[])[+[]] is "f" (the first char of "false"), (![]+[])[+!+[]]) is "a", etc...
How does it work?
Let's examine the first character, 'f':
(![]+[])[+[]]; // 'f'
The first part of the expression—between parentheses—is composed by ![]+[], the first ...
Delete duplicate rows from small table
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DELETE FROM dupes a
WHERE a.ctid <> (SELECT min(b.ctid)
FROM dupes b
WHERE a.key = b.key);
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jQuery - selecting elements from inside a element
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Actually, $('#id', this); would select #id at any descendant level, not just the immediate child. Try this instead:
$(this).children('#id');
or
$("#foo > #moo")
or
$("#foo > span")
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Cannot simply use PostgreSQL table name (“relation does not exist”)
....
In other words, the following fails:
CREATE TABLE "SF_Bands" ( ... );
SELECT * FROM sf_bands; -- ERROR!
Use double-quotes to delimit identifiers so you can use the specific mixed-case spelling as the table is defined.
SELECT * FROM "SF_Bands";
Re your comment, you can add a schema to th...
INNER JOIN ON vs WHERE clause
...ed is a cartesian product of the tables to which a filter is applied which selects only those rows with joining columns matching.
It's easier to see this with the WHERE syntax.
As for your example, in MySQL (and in SQL generally) these two queries are synonyms.
Also note that MySQL also has a STR...
MySQL SELECT WHERE datetime matches day (and not necessarily time)
...
NEVER EVER use a selector like DATE(datecolumns) = '2012-12-24' - it is a performance killer:
it will calculate DATE() for all rows, including those, that don't match
it will make it impossible to use an index for the query
It is much fas...