DAIS_COMPLET_2

ALTER TABLE Reservation ADD (confirm INT NULL);
ALTER TABLE Reservation ADD CONSTRAINT Relation_confirm FOREIGN KEY (confirm) REFERENCES Staff (idstaff);

CREATE OR REPLACE
FUNCTION CheckStaff(
              p_idUser "User".idUser%TYPE,
              p_idTrainRide TrainRide.idTrainRide%TYPE
              ) RETURN BOOLEAN AS
help INT;
CURSOR boolcurs IS SELECT * FROM Reservation WHERE idUser = p_idUser AND idTrainRide = p_idTrainRide;
BEGIN
  FOR cur IN boolcurs LOOP
    IF (cur.confirm != NULL) THEN
      help := 1;
    ELSE
      help := 0;
    END IF;
  END LOOP;

  IF (help = 0) THEN
    RETURN FALSE;
  ELSE
    RETURN TRUE;
  END IF;
END;

SET SERVEROUTPUT ON
BEGIN
IF(checkStaff(1,1) = FALSE) THEN
  DBMS_OUTPUT.PUT_LINE('FALSE');
ELSE
  DBMS_OUTPUT.PUT_LINE('TRUE');
END IF;
END;