Check if a user-defined type already exists in PostgreSQL

Question

Say I have created some user-defined types in the DB,

i.e. CREATE TYPE abc ...

Is it then possible to determine if the user-defined type exists

Answer 1

This plays well with schemas, and avoids exception handling:

DO $$
BEGIN
    IF NOT EXISTS (
      SELECT 1 FROM pg_type t
      LEFT JOIN pg_namespace p ON t.typnamespace=p.oid
      WHERE t.typname='my_type' AND p.nspname='my_schema'
    ) THEN
        CREATE TYPE my_schema.my_type AS (/* fields go here */);
    END IF;
END
$$;