Re: weird join producing too many rows
От | Gary Stainburn |
---|---|
Тема | Re: weird join producing too many rows |
Дата | |
Msg-id | 201209120917.00531.gary.stainburn@ringways.co.uk обсуждение исходный текст |
Ответ на | Re: weird join producing too many rows (Samuel Gendler <sgendler@ideasculptor.com>) |
Список | pgsql-sql |
Hi, Thanks for this. I did eventually discover the cause being other rows in the pieces_requests table that I hadn't thought about. The short answer to your second part is that I don't know why I did it that way. Presumably when I first wrote it there was a reason. Gary On Wednesday 12 September 2012 08:24:42 Samuel Gendler wrote: > I'll admit I don't see any reason why you should get duplicate rows based > on the data you've provided, but I am wondering why you are using the > subquery instead of just 'where r.r_id = 5695' > > select p.p_id, r.pr_ind > from pieces p > join pieces_requests r on p.p_id = r.p_id > where r.r_id = 5695 > > Though I'll be the first to admit that that seems to me like it ought to > return the exact same rows as both your queries. Are you sure you don't > have multiple rows in pieces_requests with the same p_id, r_id pairing? > Your join must be resulting in multiple rows for each p_id somehow. > -- Gary Stainburn Group I.T. Manager Ringways Garages http://www.ringways.co.uk
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