lter TABLE piso add habitantes NUMBER(5);

CREATE OR REPLACE PROCEDURE procedure4

IS

    v_habitantes piso.habitantes%TYPE;
    v_numero persona.numero%TYPE;
    v_calle persona.calle%TYPE;
    v_dni_c piso.dni_p%TYPE;
    CURSOR recorrido IS SELECT COUNT(dni), calle, numero, dni_c FROM persona GROUP BY calle, numero, dni_c;

BEGIN

    OPEN recorrido;

    LOOP

        EXIT WHEN recorrido%notfound;

        FETCH recorrido INTO v_habitantes, v_calle, v_numero, v_dni_c;

        UPDATE piso SET habitantes_ori = v_habitantes WHERE calle = v_calle AND numero = v_numero AND dni_p = v_dni_c;

    END LOOP;

    CLOSE recorrido;

END;
/