Re: Count the children
От | Michael Rowan |
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Тема | Re: Count the children |
Дата | |
Msg-id | A6A360DD-7CB4-4B37-824B-18086A919DA6@internode.on.net обсуждение исходный текст |
Ответ на | Re: Count the children (Mark Styles <postgres@lambic.co.uk>) |
Список | pgsql-novice |
Thanks to all who replied. I am an absolute newbie here. Of course, parent.name is not unique, so I use parent.id instead and all is well. Except that I need to return columns from the parent table such as name, phone etc. I assume this can be done using a subquery, but have no idea how it should be. Any offers? Mike On 19/08/2009, at 12:14 AM, Mark Styles wrote: > On Wed, Aug 19, 2009 at 12:04:13AM +0930, Michael Rowan wrote: >> I need what sounds like a very simple query - but I'm darned if I can >> figure it out. >> >> I have two tables, parent and child related by child.parent_id = >> parent.id >> The query should return, for each parent row, parent.name and >> number of >> child rows >> >> Can someone enlighten me, please? > > Assuming parent.name is unique: > > SELECT parent.name, count(*) > FROM parent, child > WHERE parent.key = child.parent_key > GROUP BY parent.name; > > -- > Mark > http://www.lambic.co.uk > Michael Rowan mike.rowan@internode.on.net 11 Kingscote Street ALBERTON South Australia 5014 tel 618 8240 3993
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