sql，加入2个表

Question

我有2张桌子

matchdata： id_team1，id_team2，name_team1，name_team2，group_order_id

队： team_id，team_name

我试试这个：

select * from matchdata join teams on matchdata.id_team1 = teams.team_id;

但我需要

matchdata.id_team1 = teams.team_id

和

matchdata.id_team2 = teams.team_id

之后我想要select WHERE group_order_id = $bla 我怎么能这样做？

Answer 1

您可以在一张桌子上使用两个JOIN。

SELECT * FROM matchdata
JOIN teams t1 ON matchdata.id_team1 = t1.team_id
JOIN teams t2 ON matchdata.id_team1 = t2.team_id
WHERE group_order_id = $bla;

Answer 2

您可以使用IN：

SELECT *
FROM matchdata md 
    JOIN teams t ON t.team_id IN (md.id_team1, md.id_team2)
WHERE md.group_order_id = $bla