Postgres从表行选择

Question

我有包含的表团队 像这样的列

team_id | name    | competition_id
--------+---------+------
 1      | name 1  | 10
 2      | name 2  | 10

我也有这个表夹具

fixture_id  | home_team_id | away_team_id | competition_id
    --------+--------------+--------------+--------------
     1      | 1            | 2            | 10
     2      | 2            | 1            | 10 

表夹具的主键是fixture_id，home_team_id，away_team_id， 和competition_id。 home_team，away_team和竞争也是外键。

如何从灯具中选择home_team_name，away_team_name。

Answer 1

您可以两次加入fixtures表格上的teams表格 - 一个用于主队，一个用于客队：

SELECT  fixture_id, home.name, away.name
FROM    fixtures f
JOIN    teams home on home.team_id = f.home_team_id
JOIN    teams away on away.team_id = f.way_team_id