Re: Returning a row from a function with an appended array field

From: Wes Cravens <wcravens(at)cortex-it(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: Returning a row from a function with an appended array field
Date: 2011-11-10 01:54:15
Message-ID: 4EBB2EC7.7010103@cortex-it.com
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On 11/9/2011 7:34 PM, David Johnston wrote:
> On Nov 9, 2011, at 20:19, Wes Cravens <wcravens(at)cortex-it(dot)com> wrote:
>
>> I have an adjacency list kind of table
>>
>> CREATE TABLE thingy (
>> id int,
>> parent int
>> );
>>
>> I'd like to be able to write a procedural function that returns a row or
>> rows from this table with an appended field that represents the children.
>>
>> Something like this pseudo code:
>>
>> FOR row IN SELECT * FROM thingy
>> LOOP
>> RETURN NEXT row,[SELECT id FROM thingy WHERE parent_id = id]
>> END LOOP,
>> RETURN
>>
>> Any help much appreciated,
>>
>> Wes
>>
>
> Use "WITH RECURSIVE" instead of a function.
>

I apologize but I don't know how that would work. An example would help.

Also... my pseudo code above was a little flawed:
RETURN NEXT row,[SELECT id FROM thingy WHERE parent_id = id]
should be...
RETURN NEXT row,[SELECT id FROM thingy WHERE parent_id = row.id]

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