Re: nextval on insert by arbitrary sequence

Henry House wrote:

>On Thu, Jul 19, 2001 at 07:17:20PM -0700, Dado Feigenblatt wrote:
>
>>I'm not sure if I worded the subject right, but my problem is this:
>>
>>I have a few entries in one table. Each row is the parent of many
>>entries in a second table.
>>In the second table I have a lot of entries referencing the entries on
>>the first table.
>>So far so good. Basic foreign key thing.
>>The entries on the second table need to be numbered, but instead of a
>>single sequence for all rows,
>>I need a sequence per group of rows, according to their parent record.
>>
>>I have some ideas but they are not coming together.
>>I thought of creating individual sequences for each new parent row, and
>>maybe store its name in the parent row itself, so it can be accessed by
>>it's children row.
>>But then, how do I get a field on the second table to DEFAULT to
>>nextval() on it's parent's sequence?
>>
>
>I have done this manally, by creating a sequence and the grabbing a unique
>number from the sequence using 'SELECT nextval('seq_name'). I then use this
>number in all the INSERTs.
>
>Even though it takes one extra query, it is a simple approach and PostgreSQL
>guarantees that the sequence will return unique, sequential numbers as long
>as it is used consistently.
>
You kind of implied the answer to my question.
You just does it in the client instead of using back stored
functions/triggers or contrived SQL to handle that, right?

Thanks

--
Dado Feigenblatt Wild Brain, Inc.
Technical Director (415) 553-8000 x???
dado(at)wildbrain(dot)com San Francisco, CA.