/SQL/Cannot return non-composite value from function that returns composite type

Cannot return non-composite value from function that returns composite type

--EXAMPLE OF A UPDATE FUNCTION WITH TRIGGER PLPGSQL

CREATE OR REPLACE FUNCTION update_aumentarpreco ()
    RETURNS TRIGGER
    LANGUAGE PLPGSQL
    AS 
    $BODY$
BEGIN
    IF NEW.ps_availqty = 2 THEN
        NEW.ps_supplycost = OLD.ps_supplycost * 0.10;
        RETURN NEW;
    END IF;
    RETURN NULL;
END;
$BODY$ 

CREATE TRIGGER update_aumentarpreco
    BEFORE UPDATE OF ps_availqty ON partsupp
    FOR EACH ROW
    EXECUTE PROCEDURE update_aumentarpreco ();

Similar codes

0 vote324 views1 answer
Sql get highest date from 3 tabels
SQL
0 vote333 views2 answers
Mysql set foreign_key_checks=0
SQL
1 vote317 views1 answer
SQL: merging multiple row data in string
SQL
3 votes334 views1 answer
Increment integer in table sql
SQL
0 vote287 views1 answer
Get number of table colums in sql query
SQL
2 votes313 views1 answer
Oracle drop table free up space
SQL
0 vote326 views1 answer
Sql select lowest value row
SQL
0 vote327 views1 answer
To_date sql
SQL
3 votes322 views2 answers
Sql end of month
SQL
51 votes421 views6 answers
Change column name sql
SQL