Re: On insert duplicate row, return existing key

On Jul 31, 12:36 pm, Nick <nboutel...@gmail.com> wrote:

If I insert a duplicate row into a table, id like to return the
existing key.

I tried creating a rule for this...

CREATE RULE no_duplicates AS ON INSERT TO names WHERE EXISTS (SELECT 1
FROM names WHERE new.name = name) DO INSTEAD SELECT id, name FROM
names WHERE name = new.name;

However, I get an error on...

INSERT INTO names (name) VALUES ('existing') RETURNING *;

ERROR:  cannot perform INSERT RETURNING on relation "names"
HINT:  You need an unconditional ON INSERT DO INSTEAD rule with a
RETURNING clause.