generate_series with left join
От | Pedro B. |
---|---|
Тема | generate_series with left join |
Дата | |
Msg-id | 1151510424.28638.18.camel@m3ta.msglab.mine.nu обсуждение исходный текст |
Ответы |
Re: generate_series with left join
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Список | pgsql-sql |
Greetings. I'm having some difficulties with my first use of the generate_series function. Situation:cause | integer date | timestamp(2) without time zone cause | date ------+------------+-----------+ 1 | 2006-03-23 15:07:53.63 | 2 | 2006-02-02 12:13:23.11 | 2 | 2006-11-12 16:43:11.45 | 1 | 2005-03-13 18:34:44.13 | 3 | 2006-01-23 11:24:41.31 | (etc) What i need to do, is to count the 'cause' column for the values '1' and '2', and group them by year, using left joins in order to also have the serialized years with empty values in the output. My needed output for a series of (2005,2007) would be:year | one | two ------+------+------2005 | 1 | 02006 | 1 | 22007 | 0 | 0 I have tried something like #select s, (select count(cause) from mytable where cause=1 ) as one, COUNT (cause) as two from generate_series(2006,2009) AS s(d) left JOIN mytable o ON (substr(o.date,1,4) = s.d and cause=2) GROUP BY s.d ORDER BY 1; which obviously is wrong, because of the results: s | one | two ------+------+------2006 | 3769 | 16582007 | 3769 | 02008 | 3769 | 02009 | 3769 | 0 As far as the 'two', the left join was successful, however i can not find a way to join the 'one'. The output value is correct, but the result shown should be only for the year 2006, not for all the values of the series. Maybe i've looked at it TOO much or maybe i'm completely failing to find a working logic. Any suggestions? Any and all help is humbly appreciated. \\pb -- This message has been scanned for viruses and dangerous content at MsgLab.com and is believed to be clean.
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