摘要: l 多表链接 1 笛卡尔积select * from dep,emp;select * from dep,emp where dep.id = emp.dep_id;2 内连接inner joinselect * from dep inner join emp on dep.id = emp.dep 阅读全文
posted @ 2017-12-09 12:26 荒天帝001 阅读(179) 评论(0) 推荐(0) 编辑