Re: sql interogation
От | Steven Klassen |
---|---|
Тема | Re: sql interogation |
Дата | |
Msg-id | 20041025140038.GA23440@commandprompt.com обсуждение исходный текст |
Ответ на | sql interogation ("cristivoinicaru" <cristivoinicaru@dmhi.ct.ro>) |
Список | pgsql-novice |
* cristivoinicaru <cristivoinicaru@dmhi.ct.ro> [2004-10-25 10:05:22 +0200]: > Explanations: > I want like sql interogation to select only one record from each > "gc" group record (who has the same code "gc" (that means that the > "gc" field will be unique key)) with the following two condition: > > 1)from each "gc" group of records to select the record who has the > value of "ora" field maxim. > > 2)if two ore more record have the same value of the maxim value of > the "ora" to select oly one of them Try this out; this is from memory, so it hasn't been tested. SELECT DISTINCT max(gc), co, data, ora FROM temp50 GROUP BY co, data, ora; -- Steven Klassen - Lead Programmer Command Prompt, Inc. - http://www.commandprompt.com/ PostgreSQL Replication & Support Services, (503) 667-4564
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