Dear List, i want to built an aggregate function wich should summing up values in a distinct manner:
dsum(DISTINCT ROW(value, distinction)). I implemented all things i thought i need but it dont work. i get always an 'could not identify an equality operator for type dsum_type'-error nevertheless the operator will be identified outside the aggregate. Here is the code for the equality operator: CREATE OR REPLACE FUNCTION dsum_type_greater(dsum_type, dsum_type) RETURNS boolean AS $f$ SELECT $1.distinction > $2.distinction; $f$ LANGUAGE sql IMMUTABLE STRICT; CREATE OPERATOR = ( PROCEDURE = dsum_type_equality, LEFTARG = dsum_type, RIGHTARG = dsum_type, COMMUTATOR = = ); And this happens: -- result is FALSE SELECT ROW(5, 'foo')::dsum_type = ROW(5, 'bar')::dsum_type; -- result is TRUE SELECT ROW(5, 'foo')::dsum_type = ROW(5, 'foo')::dsum_type; -- result is TRUE SELECT ROW(4, 'foo')::dsum_type = ROW(5, 'foo')::dsum_type; -- works for me SELECT dsum(ROW(wert, name)::dsum_type) FROM table1; -- ERROR: could not identify an equality operator for type dsum_type SELECT dsum(DISTINCT ROW(wert, name)::dsum_type) FROM table1; i added the less then and greater then ops too, but it still wont work. What i am doing wrong or can i achieve the wished result without usinge a comlex type? regards, Thomas! ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq