使用TOP 1分配值时出错

Question

这是导致错误的代码：

SELECT @maxNo = TOP 1 CONVERT(INT,(SUBSTRING(noorder,7,4))) 
FROM orders ORDER BY noorder DESC;

它返回：

  

Msg 156，Level 15，State 1，Line 2
关键字附近的语法不正确   '顶部'。

编辑： 找到了答案，我应该像这样编码：

select top 1 @maxNo = CONVERT(int, (SUBSTRING(noorder, 7, 4)))

来自订单 按订单排序desc;

感谢@RedFilter

Answer 1

select top 1 @maxNo = CONVERT(int, (SUBSTRING(noorder, 7, 4)))
from orders
order by noorder desc;

Answer 2

 declare @maxNo int
 Set @maxNo = (Select TOP 1 CONVERT(INT,(SUBSTRING(noorder,7,4))) 
 FROM [order] order by  noorder desc)
 select @maxNo