declare @TopCount int 
set @TopCount = 100 
select top (@TopCount) * from AdventureWorks.HumanResources.Employee 
如果有Like等字句,一定要拼Sql的话,也应该使用sp_executesql来执行,示例如下: 
declare @TopCount int --定义top 数量 
set @TopCount = 100 
declare @Title nvarchar(100) --定义like内容 
set @Title = "%n%" 
declare @SelectSql nvarchar(max) 
set @SelectSql = " 
select top (@TopCountPar) * 
from AdventureWorks.HumanResources.Employee 
where Title like @TitlePar" --使用参数化的top和like 
--使用sp_executesql 来执行,可以提高效率 
exec sp_executesql @SelectSql, 
N"@TopCountPar as int,@TitlePar as nvarchar(100)", 
@TopCountPar = @TopCount,@TitlePar = @Title