On Aug 10, 2010, at 6:15 PM, jeroen wrote:
Hi,
I have a fairly complex SQL statement I'd like to convert to AREL
SELECT count(matches.id), players.*
FROM clubs
INNER JOIN players ON players.club_id = clubs.id
INNER JOIN rankings ON rankings.player_id = players.id
INNER JOIN tournaments ON rankings.tournament_id = tournaments.id
LEFT OUTER JOIN matches ON (matches.p1_id = players.id OR
matches.p2_id = players.id)
AND clubs.id = 7
AND tournaments.id = 19
GROUP BY players.id
How would I do this?
One step at a time ...
Even though you have the query Club-centric, you're asking for
players.* so I'd start with the Player model:
Player.select('count(matches.id) as match_count, players.*')
Then you have inner joins:
.joins([:club, { :rankings => :tournament }])
And then an outer join (this is a tricky one and depends on how you've
defined the associations):
.includes(:matches)
Looks like you already know the club and the tournament:
.where(['clubs.id = ? AND tournaments.id = ?', 7, 19])
And you want the count() function to behave:
.group('players.id')
Then ask for all of 'em:
.all
That may not actually work, but it certainly ought to give you some
hints. (And there's probably other ways to get the same information,
but you need to ask a better question to get a better answer.)
-Rob
Rob Biedenharn
[email protected] http://AgileConsultingLLC.com/
[email protected] http://GaslightSoftware.com/
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