sql-server - 使用 TOP 1 赋值时出错

Question

这是我的导致错误的代码：

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

它返回：

消息 156，级别 15，状态 1，第 2 行
关键字“TOP”附近的语法不正确。

编辑：找到答案，我应该这样编码：

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

来自 noorder desc 的订单；

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