当前位置: 代码迷 >> Sql Server >> 简单的查询有关问题,
  详细解决方案

简单的查询有关问题,

热度:22   发布时间:2016-04-27 20:18:42.0
简单的查询问题,在线等。。。
declare   @tablename   as   varchar(20)  
select   @tablename   =   (select   top   1   tablename   from   user_temp   )


[email protected]
但是如果SQL语句里有变量的话,如何做能把返回值赋给变量呢,
如:select   top   1   tablename   from   user_temp   where   type= '条件 '

------解决方案--------------------
你這裡沒有必要使用動態SQL語句

declare @username as varchar(20)
declare @tablename as varchar(20)
set @username= 'bccu '
select top 1 @tablename =tablename from userinfo where [email protected]
select @tablename
------解决方案--------------------
declare @sql as varchar(100)
declare @username as varchar(20)
declare @tablename as varchar(20)
set @username= 'bccu '
set @sql = 'select top 1 @tablename =tablename from userinfo where username= ' ' '[email protected]+ ' ' ' '
exec sp_executesql @sql,N '@tablename varchar(20) output ',@tablename output
select @tablename
------解决方案--------------------
declare @sql as Nvarchar(100)
declare @username as varchar(20)
declare @tablename as varchar(20)
set @username= 'bccu '
set @sql = N 'select top 1 @tablename =tablename from userinfo where username= ' ' '[email protected]+ ' ' ' '
exe sp_executesql @sql,N '@tablename varchar(20) output ',@tablename output
select @tablename
  相关解决方案