SQL making stack-overflow trip

    CREATE TABLE parent (
      pid INTEGER PRIMARY KEY,
      expired CHAR(1));

      CREATE TABLE child (
        cid INTEGER PRIMARY KEY,
        f_pid INTEGER NOT NULL REFERENCES parent(pid) );

    INSERT INTO parent VALUES (1,'0');
    INSERT INTO parent VALUES (2,'1');
    INSERT INTO parent VALUES (3,'0');

    INSERT INTO child VALUES (1,1);
    INSERT INTO child VALUES (2,1);

    -- this should fail as the parent has expired=1
    INSERT INTO child VALUES (3,2);

    -- this should also fail as it has children referencing it
    UPDATE parent SET expired='1' WHERE pid=1;