Re: count(boolean)
От | Jean-Luc Lachance |
---|---|
Тема | Re: count(boolean) |
Дата | |
Msg-id | 3CE91F49.DC7B73C8@nsd.ca обсуждение исходный текст |
Ответ на | Re: Casting timestamp ("Joel Burton" <joel@joelburton.com>) |
Список | pgsql-sql |
Actually, "count" should be "sum" SELECT question_id AS id, sum( case when value then 1 else 0 end) as count_true, sum( case when value then 0 else 1 end)as count_false FROM answers_boolean GROUP BY question_id; I wrote: > > Dan, > > Try: > > SELECT > question_id AS id, > count( case when value then 1 else 0 end) as count_true, > count( case when value then 0 else 1 end) as count_false > FROM > answers_boolean > GROUP BY > question_id; > > jll > > Dan MacNeil wrote: > > > > I have a table answers_boolean: > > > > question_id | integer | not null > > evaluation_id | integer | not null > > value | boolean | > > > > I'd like output in the form: > > > > question_id, count_true, count_false > > > > ....where count_true is the number of questions answered "true" > > > > SELECT > > question_id AS id, value AS val , count(value) AS cnt > > FROM > > answers_boolean > > GROUP BY > > question_id,value; > > > > gives me: > > id | val | cnt > > ----+-----+----- > > 2 | f | 3 > > 2 | t | 3 > > 3 | f | 2 > > 3 | t | 4 > > > > ...which is sorta what I want. > > > > I've looked through the docs & archive but haven't found the answer. > > > > TIA > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 3: if posting/reading through Usenet, please send an appropriate > > subscribe-nomail command to majordomo@postgresql.org so that your > > message can get through to the mailing list cleanly > > ---------------------------(end of broadcast)--------------------------- > TIP 2: you can get off all lists at once with the unregister command > (send "unregister YourEmailAddressHere" to majordomo@postgresql.org)
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