Re: EXTERN JOIN with WHEN query
От | scott.marlowe |
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Тема | Re: EXTERN JOIN with WHEN query |
Дата | |
Msg-id | Pine.LNX.4.33.0306060834500.19717-100000@css120.ihs.com обсуждение исходный текст |
Ответ на | EXTERN JOIN with WHEN query (javier garcia - CEBAS <rn001@cebas.csic.es>) |
Список | pgsql-general |
On Thu, 5 Jun 2003, javier garcia - CEBAS wrote: > Hi all; > This is a query that I guess is not very difficult, but I'm a newbie; > I've got a lot of tables, each of them with two columns: > > SELECT * FROM precal; -> > (date) (real) > fecha | precipitacion > ------------+--------------- > 1996-01-01 | 0.6 > 1996-02-01 | 0.7 > ... > > > But in this table there are some inexistents records (some missing days) > And I would like to create lists with a full list of dates and corresponding > precipitation data, with gaps when the row didn't exist. > So; I've created a table with a complete series of dates from 1950 up to > date, and made the query: Any time you're gonna do this, you can make a table with all the dates in it already, and left join against that. I.e. if you want a report for every month, numbered 1 through 12, then just create a table with an id 1 to 12 and the names of the months. Since the table's so small, it doesn't even really need indexes.
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