如何解決SQL錯誤：如果「每個派生的表必須有它自己的別名」的加入

Question

我使用此查詢：

select max(counted) 
from (select max(outcome.player_of_match) counted 
from outcome 
inner join player 
on player.id=outcome.player_of_match group by player.id); 

它顯示了SQL錯誤：

Every derived table must have its own alias.

Answer 1

您只需向您正在選擇的子查詢添加別名：

select max(T1.counted) 
from (
      select  max(outcome.player_of_match) counted 
      from  outcome 
      inner join player 
        on player.id=outcome.player_of_match 
      group by player.id 
     ) AS T1;