[sql] Dynamic SELECT TOP @var In SQL Server

How can I have a dynamic variable setting the amount of rows to return in SQL Server? Below is not valid syntax in SQL Server 2005+:

DECLARE @count int
SET @count = 20

SELECT TOP @count * FROM SomeTable

This question is related to sql sql-server-2005

The answer is


The syntax "select top (@var) ..." only works in SQL SERVER 2005+. For SQL 2000, you can do:

set rowcount @top

select * from sometable

set rowcount 0 

Hope this helps

Oisin.

(edited to replace @@rowcount with rowcount - thanks augustlights)


Its also possible to use dynamic SQL and execute it with the exec command:

declare @sql  nvarchar(200), @count int
set @count = 10
set @sql = N'select top ' + cast(@count as nvarchar(4)) + ' * from table'
exec (@sql)

In x0n's example, it should be:

SET ROWCOUNT @top

SELECT * from sometable

SET ROWCOUNT 0

http://msdn.microsoft.com/en-us/library/ms188774.aspx


The syntax "select top (@var) ..." only works in SQL SERVER 2005+. For SQL 2000, you can do:

set rowcount @top

select * from sometable

set rowcount 0 

Hope this helps

Oisin.

(edited to replace @@rowcount with rowcount - thanks augustlights)


declare @rows int = 10

select top (@rows) *
from Employees
order by 1 desc -- optional to get the last records using the first column of the table

The syntax "select top (@var) ..." only works in SQL SERVER 2005+. For SQL 2000, you can do:

set rowcount @top

select * from sometable

set rowcount 0 

Hope this helps

Oisin.

(edited to replace @@rowcount with rowcount - thanks augustlights)


Or you just put the variable in parenthesis

DECLARE @top INT = 10;

SELECT TOP (@Top) *
FROM <table_name>;

The syntax "select top (@var) ..." only works in SQL SERVER 2005+. For SQL 2000, you can do:

set rowcount @top

select * from sometable

set rowcount 0 

Hope this helps

Oisin.

(edited to replace @@rowcount with rowcount - thanks augustlights)


Its also possible to use dynamic SQL and execute it with the exec command:

declare @sql  nvarchar(200), @count int
set @count = 10
set @sql = N'select top ' + cast(@count as nvarchar(4)) + ' * from table'
exec (@sql)

declare @rows int = 10

select top (@rows) *
from Employees
order by 1 desc -- optional to get the last records using the first column of the table

Or you just put the variable in parenthesis

DECLARE @top INT = 10;

SELECT TOP (@Top) *
FROM <table_name>;

Its also possible to use dynamic SQL and execute it with the exec command:

declare @sql  nvarchar(200), @count int
set @count = 10
set @sql = N'select top ' + cast(@count as nvarchar(4)) + ' * from table'
exec (@sql)

In x0n's example, it should be:

SET ROWCOUNT @top

SELECT * from sometable

SET ROWCOUNT 0

http://msdn.microsoft.com/en-us/library/ms188774.aspx


In x0n's example, it should be:

SET ROWCOUNT @top

SELECT * from sometable

SET ROWCOUNT 0

http://msdn.microsoft.com/en-us/library/ms188774.aspx