Re: how to get row number in select query
От | Thomas Kellerer |
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Тема | Re: how to get row number in select query |
Дата | |
Msg-id | ihs31q$1lm$1@dough.gmane.org обсуждение исходный текст |
Ответ на | Re: how to get row number in select query (Piotr Czekalski <pczekalski@techbaza.pl>) |
Ответы |
Re: how to get row number in select query
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Список | pgsql-sql |
Piotr Czekalski, 27.01.2011 16:21: > Gentelmen, > > I follow this thread and I don't exactly get an idea of yours, but > isn't is as simple as (example: table "web.files" contains one column > named "fileurl" ): > > select row_number() over(), X.fileurl from (select fileurl from > web.files order by fileurl) X > > The only disadvantage is that if you do want to order resultset you > have to use "select from select" as numbers are added before order > which may cause some performance troubles. > You can get the row_number() without using the sub-select and without ordering the whole result as you can specify the orderin the over() clause: select fileurl row_number() over (order by fileurl) from web.files Regards Thomas
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