CREATE OR REPLACE TRIGGER BRG_CNS_LAND_TCMP_106
BEFORE DELETE OR INSERT OR UPDATE ON
STEDEN FOR EACH ROW
    DECLARE
        l_oper varchar2 ( 3 );
        l_error_stack varchar2 ( 4000 );
    BEGIN
        IF inserting THEN
            l_oper := 'INS';
        elsif updating THEN
            l_oper := 'UPD';
        elsif deleting THEN
            l_oper := 'DEL';
        END IF;
        DECLARE
            l_passed BOOLEAN := TRUE;
            l_PROVINCIE varchar2(4000);
        BEGIN
            SELECT PROVINCIE INTO l_PROVINCIE FROM STEDEN WHERE PROVINCIE = 'Klaas';
            IF l_oper IN ('DEL', 'INS', 'UPD') THEN
                l_passed := STEDEN.LAND = l_PROVINCIE;
                IF NOT l_passed THEN
                    l_error_stack := l_error_stack || 'Niet gelijk';
                END IF;
            END IF;
        END;
    IF l_error_stack IS NOT NULL THEN
        raise_application_error ( -20800, l_error_stack );
    END IF;
END BRG_CNS_LAND_TCMP_106;