多表关联
更新时间 2025-02-05 09:36:29
最近更新时间: 2025-02-05 09:36:29
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)
