SELECT u.user_id,c1.city_name,c2.city_name,c3.city_name
FROM user u
LEFT JOIN city c1 ON u.user_birth_city=c1.city_id
LEFT JOIN city c2 ON u.user_current_city=c2.city_id
LEFT JOIN city c3 ON u.user_school_city=c3.city_id
Select b.city_id, b.city_name from user_table a, city_table b where
(a.user_birth_city=b.city_name OR a.user_current_city=b.city_name OR
a.user_school_city=b.city_name) AND user_id='(whatever your user_id is)';
2条答案
按热度按时间trnvg8h31#
使用
LEFT JOIN
在table上city
三次就可以了笔记:
user
有一张预订的table吗MySQL
,您的表名不应该是它5cnsuln72#
sql人员会评论说,由于from中的逗号,这个查询不会工作,但我向您保证,它会工作的。