mysql常用查询语法

mysql常用查询语法

1.内连接

    隐士内连接：select * from A a,B b where a.did =b.bid;

    显示内连接：select * from A a INNER JOIN B b ON a.key = b.key;

2.外链接

   左外连接：select * from A a LEFT JOIN B b ON a.fkey=b.key;

   右外连接：select * from A a RIGHT JON B b ON a.fkey=b.key;