多表关联
更新时间 2025-02-14 10:21:32
最近更新时间: 2025-02-14 10:21:32
本文为您介绍SELECT语法中多表关联的使用方法。
内连接
teledb=# select * from teledb_pg inner join teledb_pg1 on teledb_pg.id = teledb_pg1.id; id | nickname | id | nickname ----+----------+----+---------- 3 | pg | 3 | pg (1 row)左外连接
teledb=# select * from teledb_pg left join teledb_pg1 on teledb_pg.id = teledb_pg1.id; id | nickname | id | nickname ----+------------+----+---------- 1 | teledb | | 1 | hello,pgxc | | 2 | TELEDB | | 3 | pg | 3 | pg 4 | | | (5 rows)右外连接
teledb=# select * from teledb_pg right join teledb_pg1 on teledb_pg.id = teledb_pg1.id; id | nickname | id | nickname ----+----------+----+---------- | | 5 | test 3 | pg | 3 | pg (2 rows)全连接
teledb=# select * from teledb_pg full join teledb_pg1 on teledb_pg.id = teledb_pg1.id; id | nickname | id | nickname ----+------------+----+---------- 1 | teledb | | 3 | pg | 3 | pg 4 | | | 1 | hello,pgxc | | 2 | TELEDB | | | | 5 | test (6 rows)
