Question

我想知道这个SQL语句有什么问题吗？

   select *
    from
          select * from Actors where Actors.Name = "John Twain"
    inner join 
          ActorRoles  on   Actors.ActorID = ActorRoles.ActorID
    inner join
          Movies  on       ActorRoles.MovieID=Movies.MovieID

Answer 1

 select *
    from
          (select * from Actors where Actors.Name = "John Twain") AS Actors
    inner join 
          ActorRoles  on   Actors.ActorID = ActorRoles.ActorID
    inner join
          Movies  on       ActorRoles.MovieID=Movies.MovieID

像这样的子查询需要（）和＆＃34; new＆＃34;的一个表别名。结果表。

但这更好：

select *
    from Actors 
    inner join 
          ActorRoles  on   Actors.ActorID = ActorRoles.ActorID
    inner join
          Movies  on       ActorRoles.MovieID=Movies.MovieID 
where Actors.Name = "John Twain"

Answer 2

为什么不简化？

SELECT *
FROM Actors
INNER JOIN ActorRoles ON Actors.ActorID = ActorRoles.ActorID
INNER JOIN Movies ON ActorRoles.MovieID = Movies.MovieID
WHERE Actors.NAME = "John Twain"

修复此SQL语句？

2 个答案: