mysql - 遇到需要满足多个条件的 MySQL Join 问题

Question

我有两张 table rooms 和 rooms facility，我必须选择配备所需设施的房间。

如果我选择一个有一个设施的房间(id=4 - id_fu - 的设施)。使用以下查询一切正常:

SELECT u.* FROM rooms u 
JOIN facilities_r fu 
ON fu.id_uc = u.id_uc 
    AND fu.id_fu = '4' 
WHERE 1 
    AND vizibility='1' 
GROUP BY id_uc 
ORDER BY u_premium desc, id_uc DESC 

但如果我想选择设施更多的房间，假设设施 id=4，id=3 ..使用以下查询不起作用:

SELECT u.* FROM room u 
JOIN facilities_r fu 
ON fu.id_uc=u.id_uc 
    AND fu.id_fu = '4' 
    AND fu.id_fu = '3' 
WHERE 1 
    AND vizibility = '1' 
GROUP BY id_uc 
ORDER BY u_premium DESC, id_uc DESC 

我不明白为什么它不起作用，但我无法弄清楚如何放置条件。

Answer 1

您可以使用括号对条件进行分组。当您检查一个字段是否等于另一个字段时，您需要使用 OR。例如 WHERE a='1' AND (b='123' OR b='234')。

SELECT u.*
FROM rooms AS u
JOIN facilities_r AS fu
ON fu.id_uc = u.id_uc AND (fu.id_fu='4' OR fu.id_fu='3')
WHERE vizibility='1'
GROUP BY id_uc
ORDER BY u_premium desc, id_uc desc