ORA-02271: table does not have such constraint
Cause: Self-evident.
Action: Make sure the specified constraint name is correct.
ORA-02271 错误发生在用户尝试查询或操作表中不存在的约束时：
ORA-02271:table does not have such constraint
Cause: The table named in the statement does not have the indicated constraint.
Action: Enter a valid constraint name.
当用户尝试在没有特定约束的表上检索或操作数据时，将发出ORA-02271错误消息。
1.检查约束名称是否正确，如果不正确，则重新输入正确的约束名称。
2.检查表中是否存在该约束，如果不存在，可以尝试使用ALTER TABLE语句添加约束。