SQL变量问题

[lyq888]

declare @querysql1 varchar(8000)
declare @row_num1 int
set @querysql1='select @row_num1=count(*) from '+@tablename+' where [ReadDateTime]='''+@ReadDateTime+''''
执行出现:Must declare the scalar variable "@row_num1".
是怎么回事?

[glacier3d]

是不是应该在@row_num1两边加引号呢

[glacier3d]

应该是这样吧：
set @querysql1='select count(*) from '+@tablename+' where [ReadDateTime]='''+@ReadDateTime+''''

然后查询返回的值赋给@row_num1