• 2022-10-26
    已知职工和职工亲属两个关系,当职工调出时,应该从职工关系中删除该职工的元组,同时在职工亲属关系中删除对应的亲属元组, 在SQL语言中,定义这个完整性约束的短语是( )
    A: ON DELETE ALL
    B: ON DELETE RESTRICT
    C: ON DELETE SET NULL
    D: ON DELETE CASCADE