Fwd: Need r_constraint_name

[Ramesh T <rameshparnanditech@xxxxxxxxx>]

---------- Forwarded message ----------
From: Ramesh T <rameshparnanditech@xxxxxxxxx>
Date: Tue, Jul 22, 2014 at 7:50 PM
Subject: Re: [GENERAL] Need r_constraint_name
To: Adrian Klaver <adrian.klaver@xxxxxxxxxxx>

Just i'm retriving the constraint_name when  i enter child_table_name for inner query and that constraint name is checking 

parent_table on outer statement that constraint_name is equal then display the constraint name ..?but outer select is r_constraint_name

i think in postgres r_constraint_name is also include in the pg_constraints details not a seperate column in postgres for that ,if parent table have consraint_name same as the child table return from inner query that constraint_name displayed out..

 my assumption..is it corect?

from last query..

thanks in advance..

ramesh

On Tue, Jul 22, 2014 at 7:18 PM, Adrian Klaver <adrian.klaver@xxxxxxxxxxx> wrote:

On 07/22/2014 03:12 AM, Ramesh T wrote:

thank u ,

SELECT constraint_name
                 FROM information_schema.table_constraints AS tc
        WHERE     tc.table_name = p_table_name
              AND constraint_name IN (SELECT constraint_name
                                        FROM
information_schema.table_constraints AS tc
                                       WHERE     tc.table_name =
                                                    p_ref_table_name
                                             AND tc.constraint_type =
                                                    'PRIMARY KEY');

is this correct process same as above ..

but i want check "r_constraint_name" instead of "constraint_name"  in
outer statement in above code..

I am not sure you are going to find that column. I am not an Oracle user but I did find this:

http://docs.oracle.com/html/B13531_01/ap_d.htm

R_CONSTRAINT_NAME is the name of the unique constraint definition for the referenced table.

So it would seem r_constraint_name is an column name in an Oracle system view. I know of no such name in the Postgres system catalog. I am sure the same information is available, you are just going to have to be specific about what you are looking for. From the above that would seem to be the name of the unique key that a foreign key references.

Is that correct?

If so the query you show above will not work as a UNIQUE key does not necessarily have to be the PRIMARY KEY.

please let me know..

thanks in advance,
ramesh

--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx