三个表的链接查询,可以吗?请高手指点!
select userid,partnerid from a,b,c where a.useric=b.userid and b.userid=c.uid (如果uid是userid,另一个同理)
select userid,partnerid from a,b,c where a.useric=b.userid and b.userid=c.uid (如果uid是userid,另一个同理)
union
(select tomid from members as m, friends, memberdetails where (frommid = m.mid or tomid = m.mid) and m.mid = ".$this->_uid.")你的和这个很像, fromid:为加他好友的id , tomid,为别人加他为好友, 反正都为好友,试试吧!!!!
select userid,partnerid from b where userid=value)
只能查他和他好友的buylog,而不能查他的好友的好友,好友的好友的好友,--------
select buylog.* from buylog, relation where instr(concat(userid, partnerid),uid) > 0
select buylog.* from buylog,relation where buylog.uid=[userid] or (relation.partnerid=buylog.uid and relation.userid=[userid]);