join if there, blank if not
От | Gary Stainburn |
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Тема | join if there, blank if not |
Дата | |
Msg-id | 01BFEC1E.FF0A43A0@garys.ringways.co.uk обсуждение исходный текст |
Ответы |
Re: join if there, blank if not
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Список | pgsql-sql |
Hi all, I just can't get my head round this one so I hope one of you can. I've got two tables, one holding phone calls, and another holding phone numbers. I want to do a select where if the number in the calls table exists in the numbers table, the description is included otherwise the description field is blank. Unfortunately, using the select I've tried, if the number is not on the one of the tables, it's ignored. Calls table cdate date ctime time cextn char(3) cnumber x(12) Numbers table nnumber x(12) ndesc x(30) Select I tried. select c.cdate, c.ctime, c.cextn, c.cnumber n.ndesc from calls c, numbers n where c.cnumber = n.nnumber; ----------------------------------------- Gary Stainburn. Work: http://www.ringways.co.uk mailto:gary.stainburn@ringways.co.uk REVCOM: http://www.revcom.org.uk mailto:gary.stainburn@revcom.org.uk ----------------------------------------- Murphy's Laws: (327) The minute before the engineer arrives, the printer starts working. -----------------------------------------
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