摘要: select t1.id,t2.idfrom t1left join t2 on t1.id = t2.id and t1.id>1 and t2.id<>3在mysql的left join中条件放在on后面和在where后面是不同的; 1. on后面只针对于t2表进行过滤,所以上面的t1.id>1 阅读全文
posted @ 2017-11-21 18:12 Earic 阅读(174) 评论(0) 推荐(0) 编辑