Re: Joining three data sources.

Am Mittwoch, 19. Juni 2002 16:09 schrieb Masaru Sugawara:
> On Wed, 19 Jun 2002 12:33:47 +0200
>
> Janning Vygen <vygen(at)gmx(dot)de> wrote:
> > ---------------------
> > Result Inter Mailand vs. AC ROM 2:1
> > team1_id|team2_id|goals1|goals2
> > 1 2 2 1
>
> SELECT go1.game_id, go1.team1_id, go1.team2_id,
> SUM(CASE WHEN go2.team_id = go1.team1_id
> THEN go2.n ELSE 0 END) AS goals1,
> SUM(CASE WHEN go2.team_id = go1.team2_id
> THEN go2.n ELSE 0 END) AS goals2
> FROM (SELECT game_id,
> min(team_id) AS team1_id,
> max(team_id) AS team2_id
> FROM goal
> GROUP BY 1) AS go1,
> (SELECT game_id, team_id, count(*) AS n
> FROM goal
> GROUP BY 1, 2) AS go2
> WHERE go1.game_id = go2.game_id
> GROUP BY 1, 2, 3;

Oh thanks a lot. You pushed me in the right direction. i still get
headache when trying to write complicated selects. there was
something wrong in your statement but i was able to correct it by
myself. Thanks for your help!!

Are you able to type those queries in minutes?? It seems so ...
amazing!

> As for Goal table, if it has a large number of the rows, you maybe
> need to create a unique index on it.

of course. it was just an example...

kind regards
janning