[英]Esqueleto `selectDistinct` not working
selectDistinct
似乎不适合我,这可能是一个简单的错误。 查询:
info <- runDB $
E.selectDistinct $
E.from $ \(tp `E.InnerJoin` rnd `E.InnerJoin` h) -> do
E.on (rnd E.^. RoundId E.==. h E.^. HoleRound)
E.on (tp E.^. TpartTournament E.==. rnd E.^. RoundTourn)
E.where_ ((tp E.^. TpartTournament E.==. E.val tId ))
E.orderBy [E.asc (tp E.^. TpartId)]
return (tp, rnd, h)
我很确定这代表了有效的sql查询:
SELECT DISTINCT tpart.id, round.name, hole.hole_num, hole.score
from tpart
inner join round on round.tourn = tpart.tournament
inner join hole on hole.round = round.id
where tpart.tournament = 1;
为了查看结果,我有一个测试处理程序来打印结果表。 请注意,对于第1部分,第1轮,有多个孔1和孔2.在postgresql中, SELECT DISTINICT
删除了这些重复项。
TpartId, RoundName, holeNum, HoleScore
Key {unKey = PersistInt64 1}, round 1, 1, 6
Key {unKey = PersistInt64 1}, round 1, 2, 4
Key {unKey = PersistInt64 1}, round 1, 1, 6
Key {unKey = PersistInt64 1}, round 1, 2, 4
Key {unKey = PersistInt64 1}, round 1, 1, 6
Key {unKey = PersistInt64 1}, round 1, 2, 4
Key {unKey = PersistInt64 1}, round 2, 1, 3
Key {unKey = PersistInt64 1}, round 2, 2, 5
Key {unKey = PersistInt64 1}, round 2, 1, 3
Key {unKey = PersistInt64 1}, round 2, 2, 5
Key {unKey = PersistInt64 1}, round 2, 1, 3
Key {unKey = PersistInt64 1}, round 2, 2, 5
Key {unKey = PersistInt64 3}, round 1, 1, 6
Key {unKey = PersistInt64 3}, round 1, 2, 4
Key {unKey = PersistInt64 3}, round 1, 1, 6
Key {unKey = PersistInt64 3}, round 1, 2, 4
Key {unKey = PersistInt64 3}, round 1, 1, 6
Key {unKey = PersistInt64 3}, round 1, 2, 4
Key {unKey = PersistInt64 3}, round 2, 1, 3
Key {unKey = PersistInt64 3}, round 2, 2, 5
Key {unKey = PersistInt64 3}, round 2, 1, 3
Key {unKey = PersistInt64 3}, round 2, 2, 5
Key {unKey = PersistInt64 3}, round 2, 1, 3
Key {unKey = PersistInt64 3}, round 2, 2, 5
对不起,很抱歉。 任何帮助,将不胜感激!
错误是对于某个洞,洞的round
和洞的part
必须等于它们各自的部分。 此外,在这种情况下,内连接是多余的。
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