三张表,user表和role表和user_role表
我用了and查的,之后脑子想用左连接查,想不出来,只要敲一下,做个笔记
SELECT
r.*
FROM
t_user u,
t_role r,
t_user_role ur
WHERE u.`id` = ur.`user_id`
AND r.`id` = ur.`role_id`
AND u.`id` = 1;
SELECT
r.*
FROM
t_user u
LEFT JOIN t_user_role ur
ON u.`id` = ur.`user_id`
LEFT JOIN t_role r
ON ur.`role_id` = r.`id`
WHERE u.`id` = 1;