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我正在努力做到这一点，以便我创建的数据库可以适应变化。我有一个员工表，其中每一行都有一个员工中另一行的外键（这代表每个员工的经理是谁）。我想要做的是，当我完成交换两名员工职位的交易时，外键在交易后具有正确的值。

例如，如果我们有：

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

我们在单个事务中交换 notboss 和 less boss 的职位和外键，我们希望结果表如下所示：

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

我实现这些更改的方法是创建一个在更新 jobTitle 时触发的触发器。它将查找具有先前外键的所有行并将其更改为具有旧值 jobTitle 的行中的 fk 的值。出于某种原因，我的 CREATE TRIGGER 出现编译错误。我已经在下面发布了我的代码。

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;

我不确定这是否是解决我的问题的最佳方法，因此，如果我以错误的方式解决此问题，或者您有更好的主意，请告诉我。无论哪种方式，我仍然想知道为什么会出现此编译错误。

编辑：忘记了我得到的错误。

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.

编译错误：

Error(2,1): PL/SQL: SQL Statement ignored
Error(2,97): PL/SQL: ORA-00904: "OLD"."MANAGER"."JOBTITLE": invalid identifier
4

1 回答 1

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没有看到错误很难修复，但您可以尝试：

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);
于 2013-10-11T00:01:36.737 回答