JOIN 语句详解

功能概述

JOIN 语句是 SQL 中用于连接多个表的核心操作，它基于表之间的关联关系将数据组合在一起，形成更完整的数据视图。

INNER JOIN

select * from sx1 join sx2 on sx1.sid = sx2.sid

FULL JOIN

select * from sx1 full join sx2 on sx1.sid = sx2.sid

LEFT JOIN

select * from sx1 left join sx2 on sx1.sid = sx2.sid

LEFT SEMI JOIN

select * from sx1 left semi join sx2 on sx1.sid = sx2.sid

LEFT ANTI JOIN

select * from sx1 left anti join sx2 on sx1.sid = sx2.sid

RIGHT JOIN

select * from sx1 right join sx2 on sx1.sid = sx2.sid

RIGHT SEMI JOIN

select * from sx1 right semi join sx2 on sx1.sid = sx2.sid

RIGHT ANTI JOIN

select * from sx1 right anti join sx2 on sx1.sid = sx2.sid

NATURAL JOIN

select * from sx1 natural join sx2

CROSS JOIN

select * from sx1 cross join sx2