Oracle數據庫觸發器編譯問題

Question

我正在嘗試使它能夠使我創建的數據庫適應變化。 我有一個雇員表，其中每一行都有雇員另一行的外鍵（這表示每個雇員的經理是誰）。 我想做的是，這樣當我完成一個交換兩名雇員的職位的交易時，外鍵在交易后具有正確的值。

例如，如果我們有：

ID | jobTitle | fk
1    superboss  1
2    boss       1
3    lessboss   2
4    notboss    3

並且我們在一次交易中交換了notboss和更少的boss的職稱和外鍵，我們希望終點表如下所示：

ID | jobTitle | fk
1    superboss  1
2    lessboss   3
3    boss       1
4    notboss    2

我實現這些更改的方式是通過創建一個在jobTitle更新時觸發的觸發器。 它將找到所有具有先前外鍵的行，並將其更改為具有jobTitle舊值的行中的fk值。 由於某種原因，我在CREATE TRIGGER上遇到編譯錯誤。 我已經在下面發布了我的代碼。

CREATE TABLE EmployeeB
(
    employeeID integer,
    firstName varchar (255),
    lastName varchar (255),
    phone integer,
    jobTitle varchar (255),
    payGrade integer,
    fk_EmployeeemployeeID integer,
    PRIMARY KEY(employeeID),
    FOREIGN KEY(fk_EmployeeemployeeID) REFERENCES EmployeeB (employeeID) 
ON DELETE SET CASCADE
);

CREATE OR REPLACE TRIGGER ManagerTrigger1A
AFTER UPDATE OF jobTitle ON employeeB 
REFERENCING OLD AS OldRow NEW AS NewRow  
BEGIN
UPDATE employeeB SET FK_EMPLOYEEEMPLOYEEID = (SELECT employeeID FROM employeeB WHERE jobTitle = :OldRow.jobTitle AND rownum <2) 
WHERE (SELECT employeeID FROM employeeB WHERE jobTitle = :OldRow.jobTitle) != null;
END;

CREATE OR REPLACE TRIGGER ManagerTrigger1B
AFTER UPDATE OF jobTitle ON employeeB 
REFERENCING OLD AS OldRow NEW AS NewRow  
BEGIN
DELETE FROM employeeB WHERE (SELECT employeeID FROM employeeB WHERE jobTitle = :OldRow.jobTitle) = null;
END;

我不確定這是否是解決問題的最佳方法，所以如果我以錯誤的方式進行操作，或者您有更好的主意，請告訴我。 無論哪種方式，我仍然想知道為什么會出現此編譯錯誤。

編輯：忘記了我得到的錯誤。

Error starting at line 1 in command:
CREATE OR REPLACE TRIGGER ManagerTrigger1A
AFTER UPDATE OF jobTitle ON employeeB 
REFERENCING OLD AS OldRow NEW AS NewRow  
BEGIN
UPDATE employeeB SET FK_EMPLOYEEEMPLOYEEID = (SELECT employeeID FROM employeeB WHERE jobTitle = :OldRow.jobTitle AND rownum <2) 
WHERE (SELECT employeeID FROM employeeB WHERE jobTitle = :OldRow.jobTitle) != null;
END;
Error report:
ORA-04082: NEW or OLD references not allowed in table level triggers
04082. 00000 -  "NEW or OLD references not allowed in table level triggers"
*Cause:    The trigger is accessing "new" or "old" values in a table trigger.
*Action:   Remove any new or old references.

編譯錯誤：

Error(2,1): PL/SQL: SQL Statement ignored
Error(2,97): PL/SQL: ORA-00904: "OLD"."MANAGER"."JOBTITLE": invalid identifier

Answer 1

沒有看到錯誤，很難修復它，但是您可以嘗試：

UPDATE employeeB SET FK_EMPLOYEEEMPLOYEEID = (SELECT employeeID FROM employeeB WHERE jobTitle = :OldRow.jobTitle AND rownum <2) 
WHERE EXISTS (SELECT employeeID FROM employeeB WHERE jobTitle = :OldRow.jobTitle);

和

DELETE FROM employeeB WHERE NOT EXISTS (SELECT employeeID FROM employeeB WHERE jobTitle = :OldRow.jobTitle);