变量给变量怎么赋值

[shuql]

declare @ExecStr varchar(1000)
DECLARE @TableId VARCHAR(100)
DECLARE @InfoFieName VARCHAR(100)
DECLARE @InfoTableNames VARCHAR(100)
DECLARE @Attribute VARCHAR(100)
declare @ss varchar(100)
set @InfoFieName='ProductName'
set @InfoTableNames='dbo.PRODUCT_INFO'
set @TableId='ProductId'
set @Attribute='13'
SET @ExecStr='SELECT '+@InfoFieName+' FROM '+@InfoTableNames+' WHERE '+@TableId+'='''+@Attribute+''''
EXEC (@ExecStr)
print @ss
怎么把变量@InfoFieName查询出来的值赋给@ss 然后输出
@ExecStr='SELECT '+@ss+'='+@InfoFieName+' FROM '+@InfoTableNames+' WHERE '+@TableId+'='''+@Attribute+''''我这样写是不是错的？运行没反应，请高手们指教指教。。。

[zhwh1981]

同意3楼的

[chuifengde]

declare @ExecStr nvarchar(1000)
DECLARE @TableId nVARCHAR(100)
DECLARE @InfoFieName nVARCHAR(100)
DECLARE @InfoTableNames nVARCHAR(100)
DECLARE @Attribute nVARCHAR(100)
declare @ss nvarchar(100)
set @InfoFieName='ProductName'
set @InfoTableNames='dbo.PRODUCT_INFO'
set @TableId='ProductId'
set @Attribute='13'
SET @ExecStr='SELECT @ss='+@InfoFieName+' FROM '+@InfoTableNames+' WHERE '+@TableId+'='''+@Attribute+''''

EXEC sp_executesql @ExecStr,N'@ss nvarchar(100) out',@ss OUT 

print @ss

[飘零一叶]

declare @ExecStr varchar(1000)
DECLARE @TableId VARCHAR(100)
DECLARE @InfoFieName VARCHAR(100)
DECLARE @InfoTableNames VARCHAR(100)
DECLARE @Attribute VARCHAR(100)
declare @ss varchar(100)
set @InfoFieName='ProductName'
set @InfoTableNames='dbo.PRODUCT_INFO'
set @TableId='ProductId'
set @Attribute='13'
SET @ExecStr='SELECT @ss='+@InfoFieName+' FROM '+@InfoTableNames+' WHERE '+@TableId+'='''+@Attribute+''''
EXEC sp_executesql @ExecStr,N'@ss AS varchar(100) OUTPUT',@ss OUTPUT
select @ss