MYSQL LEFT JOIN多个表两次 [英] MYSQL LEFT JOIN Multiple Tables Twice

问题描述

我有以下MySQL代码:

I have following MySQL Code:

SELECT * 
FROM b_movies, b_mov_rol_celeb, b_starcast 
LEFT JOIN bb_celebs ON b_mov_rol_celeb.celeb_id = bb_celebs.celeb_id 
  OR b_starcast.celeb_id = bb_celebs.celeb_id 
LEFT JOIN bb_roles ON b_mov_rol_celeb.role_id = bb_roles.role_id 
WHERE b_movies.id = '14';

出现错误:

"on子句"中的未知列"b_mov_rol_celeb.celeb_id"

Unknown column 'b_mov_rol_celeb.celeb_id' in 'on clause'

推荐答案

尝试一下:

SELECT m.title_slug, m.title, m.release_date,
       c.celeb_slug, c.celeb_name, 
       r.role_name,
       s.char_name
FROM b_movies m
INNER JOIN b_starcast s ON m.id = s.movie_id
INNER JOIN b_mov_rol_celeb mrc ON m.id = mrc.movie_id
LEFT JOIN bb_celebs c ON mrc.celeb_id = c.celeb_id OR s.celeb_id = c.celeb_id 
LEFT JOIN bb_roles r ON mrc.role_id = r.role_id 
WHERE m.id = '14';

表的顺序在左联接或右联接中很重要.

The order of the tables matters in a left or right join.

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