sql - 从 TOP 数量的记录中获取 MAX 值

Question

我有以下 MS SQL 查询

select top 10 RegisterTime
from  orderNotifications
order by RegisterTime asc

如何获取该查询的最大RegisterTime？

我已经尝试过了

select max(RegisterTime) in (
    select top 10 RegisterTime
    from  orderNotifications
    order by RegisterTime asc
)

但是我得到了

Msg 156, Level 15, State 1, Line 1 Incorrect syntax near the keyword 'in'.

Msg 156, Level 15, State 1, Line 4 Incorrect syntax near the keyword 'order'.

Answer 1

使您的 TOP 10 查询成为子查询:

SELECT MAX(RegisterTime)
FROM (SELECT TOP 10 RegisterTime
      FROM orderNotifications
      ORDER BY RegisterTime
      )sub