在合成SQL中。如何给变量赋值。。
不合成的SQL给变量赋值如下:
declare @aa int
select @aa=count(*) from tb下面都是语法有问题的:
set @aa = exec(@sql) 语法出错
exec(‘select @aa=count(*) from tb’) 找不到 @aa变量
不合成的SQL给变量赋值如下:
declare @aa int
select @aa=count(*) from tb下面都是语法有问题的:
set @aa = exec(@sql) 语法出错
exec(‘select @aa=count(*) from tb’) 找不到 @aa变量
Select @s=N'use pubs Declare @str char(10) set @str='+ Quotename('Smith','''')+' Select * from authors where au_lname=@str'
exec (@s)
/******************************************************************************************************************************************************
动态语句语法:exec\sp_executesql语法整理人:中国风(Roy)日期:2008.06.06
******************************************************************************************************************************************************/
--动态语句语法:--方法1查询表改为动态
select * from sysobjects
exec('select ID,Name from sysobjects')
exec sp_executesql N'select ID,Name from sysobjects'--多了一个N为unicode--方法2:字段名,表名,数据库名之类作为变量时,用动态SQL
declare @FName varchar(20)
set @FName='ID'
exec('select '+@FName+' from sysobjects where '+@FName+'=5' )
declare @s varchar(1000)
set @s=N'select '+@FName+' from sysobjects where '+@FName+'=5'
exec sp_executesql @s--会报错
declare @s nvarchar(1000)--改为nvarchar
set @s=N'select '+@FName+' from sysobjects where '+@FName+'=5'
exec sp_executesql @s--成功
--方法3:输入参数declare @i int,@s nvarchar(1000)
set @i=5
exec('select ID,Name from sysobjects where ID='+@i)set @s='select ID,Name from sysobjects where ID=@i'
exec sp_executesql @s,N'@i int',@i--此处输入参数要加上N--方法4:输出参数declare @i int,@s nvarchar(1000)
set @s='select @i=count(1) from sysobjects'--用exec
exec('declare @i int '+@s+' select @i')--把整个语句用字符串加起来执行--用sp_executesql
exec sp_executesql @s,N'@i int output',@i output--此处输出参数要加上N
select @i
--方法5:输入输出--用sp_executesql
declare @i int,@con int,@s nvarchar(1000)
set @i=5
select @s='select @con=count(1) from sysobjects where ID>@i'
exec sp_executesql @s,N'@con int output,@i int',@con output ,@i
select @con--用exec
declare @i int,@s nvarchar(1000)
set @i=5
select @s='declare @con int select @con=count(1) from sysobjects where ID>'+rtrim(@i)+' select @con'
exec(@s)本文来自CSDN博客,转载请标明出处:http://blog.csdn.net/htl258/archive/2009/04/25/4106390.aspx
--方法4:输出参数declare @i int,@s nvarchar(1000)
set @s='select @i=count(1) from sysobjects'--用exec
exec('declare @i int '+@s+' select @i')--把整个语句用字符串加起来执行--用sp_executesql
exec sp_executesql @s,N'@i int output',@i output--此处输出参数要加上N
select @i
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exec(‘select '+@aa+'=count(*) from tb’)