--發現是啟用外鍵約束時報的錯alter table DM_VOLREV enable constraint VR_VOLID_FK;

1> 先不驗證已有數據的CONSTRANT,加上參數NOVALIDATE.*/ALTER TABLE PN_POST ADD CONSTRAINT POST_CLOB_FK FOREIGN KEY (POST_BODY_ID) REFERENCES PN_POST_BODY_CLOB (OBJECT_ID) NOVALIDATE;--2>首先查看兩個表對應起來的數據有多少select count(*) from dm_volrev t,DM_VOLID k where t.vr_volid = k.vi_volid;--再分別查看單獨的數據，發現外鍵表多了一行select count(*) from dm_volrev t;select count(*) from DM_VOLID k;-找到多的行并刪除select t.vr_volid from dm_volrev t where t.vr_volid not in (select k.vi_volid from DM_VOLID k);delete from dm_volrev t where t.vr_volid = 479908;--直接重新執行啟用外鍵的語句，或者刪除之前的外鍵創建新的外鍵alter table DM_VOLREV drop constraint VR_VOLID_FK;ALTER TABLE DM_VOLREV ADD CONSTRAINT VR_VOLID_FK foreign KEY (VR_VOLID) references DM_VOLID(VI_VOLID) VALIDATE;/*啟用約束:enable( validate) :啟用約束,創建索引,對已有及新加入的數據執行約束.enable novalidate :啟用約束,創建索引,僅對新加入的數據強制執行約束,而不管表中的現有數據.禁用約束:disable( novalidate):關閉約束,刪除索引,可以對約束列的數據進行修改等操作.disable validate :關閉約束,刪除索引,不能對表進行 插入/更新/刪除等操作.*/