group by and order by question

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Тема group by and order by question
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Msg-id 20001224125304.A29047@over-yonder.net
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Ответы Re: group by and order by question  ("Oliver Elphick" <olly@lfix.co.uk>)
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Here is the table I am using:
db=> \d links
                             Table "links"
 Attribute  |  Type   |                    Modifier
------------+---------+------------------------------------------------
 id         | integer | not null default nextval('links_id_seq'::text)
 url        | text    |
 link_text  | text    |
 type       | integer |
 disp_place | integer | default nextval('links_place_seq'::text)
Indices: links_disp_place_key,
         links_id_key

'type' references an id column in a table of link types.
I need to group rows by the type but order them within each group
by 'disp_place'. (See result example below.)

Will I have to use seperate queries for each "type"?
foreach (select distinct type from links order by type)
    select url, link_text from links where type='<type>' order by disp_place

The issue is that rows with type=2 may have values of disp_place that are
between rows with type=1.

So the table would look like:
id|   url   |link_text | type |disp_place
--+---------+----------+------+----------
1 | myurl   | My URL   | 1    | 1
2 | yoururl | Your URL | 2    | 3
3 | hisurl  | His URL  | 1    | 4

I would need a result like
type | url     | disp_place
-----+---------+----------
 1   | myurl   |  1
 1   | hisurl  |  4
 2   | yoururl |  3
etc.

Thank you all for you help.
Pointers to documentation, etc. are welcomed of course.

dan


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