Mysql 如何内部联接表A+;B和参考表A到多个其他表
Im当前已成功地在表a+B之间执行外部联接,如下所示:Mysql 如何内部联接表A+;B和参考表A到多个其他表,mysql,Mysql,Im当前已成功地在表a+B之间执行外部联接,如下所示: SELECT * FROM player_img LEFT OUTER JOIN user_play ON player_img.player_img_id = user_play.user_play_entry_player_img_id AND user_play.user_play_uid = 1 WHERE player_img.player_img_id IS null 这提供了表A中的所有结果,这些结果没有任何
SELECT * FROM player_img
LEFT OUTER JOIN user_play
ON player_img.player_img_id = user_play.user_play_entry_player_img_id
AND user_play.user_play_uid = 1
WHERE player_img.player_img_id IS null
这提供了表A中的所有结果,这些结果没有任何来自表B的user\u play\u uid=1
在表A中,我有引用其他表的属性——我也希望查询出这些字段。一些表引用的快速示例:
TABLE_A:
player_img_id (unique key)
player_img_player_id (reference to: TABLE_C "player_id")
player_img_category_id (reference to: TABLE_D "category_id")
TABLE_B:
user_play_entry_player_img_id (reference to TABLE_A: "player_img_id")
user_play_uid (reference to table with user.id)
TABLE_C:
player_id (unique key)
player_country (reference to table with country.id)
player_league (reference to table with league.id)
TABLE_D:
category_id (unique key)
我想我可以按照以下方式做一些事情(当然这根本不起作用):
SELECT u . * , up . * , pi . * , p . * , c . *
FROM user u, user_play up, player_img pi, player p, country c
LEFT OUTER JOIN up
ON pi.player_img_id = up.user_play_entry_player_img_id
WHERE pi.player_img_id IS null
AND up.user_play_uid = $this->user_id
AND pi.player_img_category_id = $this->category_id
AND pi.player_img_player_id = p.player_id
AND p.player_country = c.country_id
关于如何将外部联接与跨数据库的引用查找表结合起来,有什么建议吗
编辑:
当前尝试以下建议-查询正在运行,但未显示结果-想法?:/
SELECT u . * , up . * , pi . * , p . * , c . *
FROM user u
INNER JOIN player_img pi
ON pi.player_img_category_id = 3
INNER JOIN player p
ON pi.player_img_player_id = p.player_id
INNER JOIN country c
ON p.player_country = c.country_id
LEFT OUTER JOIN user_play up
ON pi.player_img_id = up.user_play_entry_player_img_id
WHERE pi.player_img_id IS null
AND up.user_play_uid != 1
使用ANSI-92
JOIN
语法,而不是您正在使用的旧语法:
SELECT u . * , up . * , pi . * , p . * , c . *
FROM user u
INNER JOIN player_img pi ON ...
INNER JOIN player p ON pi.player_img_player_id = p.player_id
INNER JOIN country c ON p.player_country = c.country_id
LEFT OUTER JOIN user_play up ON pi.player_img_id = up.user_play_entry_player_img_id
WHERE pi.player_img_id IS null
AND up.user_play_uid = $this->user_id
注意事项:
- 您的查询中没有关于如何
将
与表
与其他表连接的条件player\u img pi
- 条件
可能会删除由于和up.user\u play\u uid=$this->user\u id
左连接而出现的不匹配行。在这种情况下,您可能需要将该条件移动到子查询中,而不是直接将该表移动到
左外部连接中
内部连接player\u img pi ON pi.player\u img\u category\u id=3
它与其他表的关系如何?