Question

That title is presumably awfully worded. I have some PostgreSQL tables. There is a bridge table, that also holds extra data, so not strictly a bridge, but acts that way also. It goes something like so:

player_game
===========
player_game_id PK
player_id FK -> player
game_id FK -> game
other stuff.

I want to compile a list of all such game_ids that contain two players of my choice.

So I could find for example, games in which player 1234 played with player 9876.

There can be between 2 and 10 players in a game.

Answer 1

select pg1.game_id from player_game pg1
inner join player_game pg2 on pg1.game_id = pg2.game_id
where pg1.player_id = 1234
and pg2.player_id = 9876
group by pg1.game_id -- or : AND  pg1.player_game_id < pg2.player_game_id