1. 内链接
select a.*,b.* from a,b where a.aa=b.bb;
等于select a.*,b.* from a inner join b on a.aa=b.bb;
等于select a.*,b.* from a join b on a.aa=b.bb;
2. 外连接
select a.*,b.* from a right join b on a.aa=b.bb;
select a.*,b.* from a left join b on a.aa=b.bb;
本文共 300 字，大约阅读时间需要 1 分钟。
1. 内链接
select a.*,b.* from a,b where a.aa=b.bb;
等于select a.*,b.* from a inner join b on a.aa=b.bb;
等于select a.*,b.* from a join b on a.aa=b.bb;
2. 外连接
select a.*,b.* from a right join b on a.aa=b.bb;
select a.*,b.* from a left join b on a.aa=b.bb;
转载于:https://www.cnblogs.com/duaner92/p/10684031.html