• 2022-10-26
    有职工和亲属两个关系,当职工调出时,应该从职工关系中删除该职工的元组,同时应该从亲属关系中删除该职工所有亲属的元组,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 CASCADE
    C: ON DELETE RESTRICT
    D: ON DELETE SET NULL