Re: Aggregates
От | Richard Huxton |
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Тема | Re: Aggregates |
Дата | |
Msg-id | 467A7B82.9030305@archonet.com обсуждение исходный текст |
Ответ на | Aggregates (Naz Gassiep <naz@mira.net>) |
Ответы |
Re: Aggregates
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Список | pgsql-general |
Naz Gassiep wrote: > Hi, > If I have a table with users and a table with messages, is it > possible to have a query that returns user.* as well as one extra column > with the number of messages they have posted and the data and time of > the last message? At the moment I am using a subquery to do this, > however it seems suboptimal. Is there a better way? Not really. You have three separate queries really: 1. User details 2. Total number of messages posted 3. Details on last message posted Unless you have a messaging-summary table that you keep up-to-date with triggers you're looking at a three-part query. -- Richard Huxton Archonet Ltd
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