CREATE OR REPLACE TRIGGER trg_update_park_capacity before
INSERT OR DELETE ON parkingslot
    FOR each ROW
DECLARE
    eletric_cap   park.eletric_capacity%TYPE;
    non_eletric_cap   park.non_eletric_capacity%TYPE;
    pa park.id_park%TYPE;
    btype bicycletype.id_bicycle_type%TYPE;
BEGIN
    pa :=:NEW.id_park;
    SELECT eletric_capacity
    INTO eletric_cap
    FROM park
    WHERE id_park = pa;
    SELECT non_eletric_capacity
    INTO non_eletric_cap
    FROM park
    WHERE id_park = pa;
    IF inserting THEN
        btype :=:NEW.id_bicycle_type;
        IF btype = 1 THEN
            eletric_cap:= eletric_cap + 1;
        ELSE
            non_eletric_cap:= non_eletric_cap + 1;
        END IF;
    ELSE
        btype :=:NEW.id_bicycle_type;
        IF btype = 1 THEN
            eletric_cap:= eletric_cap - 1;
        ELSE
            non_eletric_cap:= non_eletric_cap - 1;
        END IF;
    END IF;
    UPDATE park
    SET eletric_capacity = eletric_cap, non_eletric_capacity = non_eletric_cap
    WHERE id_park = pa;
END trg_update_park_capacity;