How to pass a record to a PL/pgSQL function?

Question

I have 8 similar PL/pgSQL functions; they are used as INSTEAD OF INSERT/UPDATE/DELETE triggers on views to make them writable. The views each combine columns of

Answer 1

There are various options, depending on the complete picture.
Basically, your insert function could work like this:

CREATE FUNCTION insert_thing (_thing flavored_view)
   RETURNS int AS
$func$
   INSERT INTO things (name) VALUES ($1.name) -- plus 30 more columns
   RETURNING id;
$func$ LANGUAGE sql;

Using the row type of the view, because NEW in your trigger is of this type.
Use a simple SQL function, which can be inlined and might perform better.

Demo call:

SELECT insert_thing('(1, foo, 1, bar)');

Inside your trigger flavored_trig ():

inserted_id := insert_thing(NEW);

Or, basically rewritten:

IF TG_OP = 'INSERT' THEN
   INSERT INTO flavored_things(thing_id, flavor)
   VALUES (insert_thing(NEW), NEW.flavor);
   RETURN NEW;
ELSIF ...

record is not a valid type outside PL/pgSQL, it's just a generic placeholder for a yet unknown row type in PL/pgSQL) so you cannot use it for an input parameter in a function declaration.

For a more dynamic function accepting various row types you could use a polymorphic type. Examples:

• How to return a table by rowtype in PL/pgSQL
• Refactor a PL/pgSQL function to return the output of various SELECT queries
• How to write a function that returns text or integer values?

Answer 2

Basically you can convert a record to a hstore variable and pass the hstore variable instead of a record variable to a function. You convert record to hstore i.e. so:

DECLARE r record; h hstore;
h = hstore(r);

Your helper function should also be changed so:

CREATE FUNCTION insert_thing (new_thing hstore) RETURNS INTEGER AS $fun$
DECLARE
    inserted_id  INT;
BEGIN
    INSERT INTO things (name) VALUES (
        new_thing -> 'name'
        -- (plus 30 more columns)
    ) RETURNING id INTO inserted_id;
    RETURN inserted_id;
END;
$fun$ LANGUAGE plpgsql;

And the call:

inserted_id = insert_thing(hstore(NEW));

hope it helps

Answer 3

Composite types. PostgresSQL has documentation on this, you essentially need to use something like

'()' or ROW() to construct the composite type for a row to pass into a function.