Thread: Re: How do I list foreign key info/relation

Hi,

Thanks for that. My problem now is it would be nice to have a way to get this
in one SQL query. I can't find a way to split up the pg_trigger.tgargs column
up into components. The data I need is separated by "\000", but the column type
is bytea. How do I split it up? I've tried using instr and substr, but I can't
get them to work.

Thankyou for your help,
Jason Davies.

--- Stephan Szabo <sszabo@megazone23.bigpanda.com> wrote:
>
> AFAIK, right now all you can do is use pg_trigger and that is how pg_dump
> is reading the constraint information.
>
> On Mon, 13 Nov 2000, Jason Davies wrote:
>
> > Hi,
> >
> > Sorry if this is a re-post. Could someone tell me how I can list the
> foreign
> > key info for a given column or for a given table?
> >
> > All I want is the information about the relationships for a specified
> column.
> > The best I've come up with so far is looking in the pg_trigger table, but
> this
> > is not ideal. There must be a way, because pg_dump gets the relationships
> > somehow.
>


=====
Jason Davies,

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Unfortunately I don't think there's a good way to do it in SQL itself.
You might be able to do something in one of the procedural
languages.  When i did the support for the older pg_dump (which may
look nothing like the current one), all I did was enhance the code that
was already there to handle constraint triggers.

You will probably have to break it up on the client side.  If I get a
chance to do computer stuff other than job related stuff I'm probably
going to write something that will return a constraint string for fk
constraints that look like the original statement (plus or minus a
little).

Stephan Szabo
sszabo@bigpanda.com

On Mon, 13 Nov 2000, Jason Davies wrote:

> Thanks for that. My problem now is it would be nice to have a way to get this
> in one SQL query. I can't find a way to split up the pg_trigger.tgargs column
> up into components. The data I need is separated by "\000", but the column type
> is bytea. How do I split it up? I've tried using instr and substr, but I can't
> get them to work.