/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

1 vote217 views2 answers
Mysql show views
SQL
0 vote230 views3 answers
How to assign custom id in mysql
SQL
36 votes274 views6 answers
Change column data type sql
SQL
0 vote229 views1 answer
Mysql aspas simples
SQL
0 vote213 views1 answer
Safe mysql
SQL
6 votes228 views2 answers
Sql sequence
SQL
0 vote207 views1 answer
View acl table oracle
SQL
0 vote234 views1 answer
Create a view in sqlite
SQL
0 vote172 views1 answer
Mysql select top 2
SQL
0 vote225 views1 answer
Sql server change schema of a table
SQL