Execute Dynamic SQL commands in SQL Server

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In some applications having hard-coded SQL statements is not appealing, because of the dynamic nature of the queries being issued against the database server. Because of this sometimes there is a need to dynamically create a SQL statement on the fly and then run that command. This can be done quite simply from the application perspective where the statement is built on the fly whether you are using ASP.NET , ColdFusion or any other programming language. But how do you do this from within a SQL Server stored procedure? SQL Server offers a few ways of running a dynamically built SQL statement. These ways are: Writing a query with parameters Using EXEC Using sp_executesql Writing a query with parameters This first approach is pretty straightforward if you only need to pass parameters into the WHERE clause of your SQL statement. Let’s say we need to find all records from the Customers table where City = ‘London’. This can be done easily as the following example shows. ...
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Sort A SQL Server Table With CASE Or CHARINDEX

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Let's say you have a table with states in your database, you only have 3 values NY, ME and SC.
You want to order the result like this: first NY followed by SC and ME last.
You can do that in two different ways
One: use a case statement in your order by
Two: use Charindex in your order by
Let's see how that works

CREATE TABLE #TEST (
STATE CHAR(2))

INSERT INTO #TEST
SELECT 'ME' UNION ALL
SELECT 'ME' UNION ALL
SELECT 'ME' UNION ALL
SELECT 'SC' UNION ALL
SELECT 'NY' UNION ALL
SELECT 'SC' UNION ALL
SELECT 'NY' UNION ALL
SELECT 'SC'

-- order by using CASE


SELECT *
FROM #TEST
ORDER BY CASE STATE
WHEN 'NY' THEN 1
WHEN 'SC' THEN 2
ELSE 3
END


--Order by using CHARINDEX
SELECT *
FROM #TEST
ORDER BY CHARINDEX(STATE,'NY-SC-ME')

--or without NY since CHARINDEX will return 0 for NY and it will be first
SELECT *
FROM #TEST
ORDER BY CHARINDEX(STATE,'SC-ME')


--the problem is of course if you have more values and you only want to have NY and SC showing up first and second
--let's insert 2 more rows
INSERT INTO #TEST
SELECT 'IL'
UNION ALL
SELECT 'CA'

-- Now the CHARINDEX Order doesn't work
-- the trick is to make it Descending and switch the states around
SELECT *
FROM #TEST
ORDER BY CHARINDEX(STATE,'SC-NY') DESC

or this way

--Order by using CHARINDEX DESC
SELECT *
FROM #TEST
ORDER BY CHARINDEX(STATE,'ME-SC-NY') DESC

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