摘要：
查询语句：select * from courseware c left join user_cour uc on c.cid = uc.cid left join `user` u on uc.uid = u.uid where u.uid=1; 表格：user user_cour cour表格 阅读全文
摘要：
user表格 user—cour表格关联表 cour表格 查询语句：select * from courseware c left join user_cour uc on c.cid = uc.cid left join `user` u on uc.uid = u.uid where u.uid 阅读全文