Update trigger

/*EXAMPLE OF A UPDATE FUNCTION WITH TRIGGER PLPGSQL*/

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

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

/*DROP TRIGGER update_aumentarpreco ON partsupp*/
/*Testing

UPDATE
    partsupp
SET
    ps_availqty = 4
WHERE
    ps_suppkey = 2*/

Similar codes

3 votes172 views2 answers
Mysql update row
SQL
0 vote229 views5 answers
Right join
SQL
0 vote187 views3 answers
Sql drop all tables
SQL
0 vote179 views1 answer
EneratingSchemaError: Some errors occurred while generating GraphQL schema: Type Query must define one or more fields.
SQL
4 votes166 views4 answers
Date less than in sql
SQL
0 vote178 views1 answer
Cannot pip install mysqlclient
SQL
0 vote170 views1 answer
Sql server order by nulls last
SQL
0 vote168 views1 answer
Show size of all tables postgres
SQL
0 vote193 views1 answer
Mysql get only the field names in a table
SQL
1 vote380 views1 answer
Foreign key in oracle sql developer
SQL