Question

我写了一个CREATE TRIGGER，但由于某种原因，我无法让它没有编译错误。有任何想法吗？这是代码和错误消息：

CREATE OR REPLACE TRIGGER  ManagerDeleteTrigger
AFTER DELETE ON employee1
REFERENCING
OLD AS OldRow
NEW AS NewRow
FOR EACH ROW
WHEN(OldRow.FK_EMPLOYEEEMPLOYEEID != NewRow.FK_EMPLOYEEEMPLOYEEID)
UPDATE employee1 SET FK_EMPLOYEEEMPLOYEEID = null WHERE FK_EMPLOYEEEMPLOYEEID = OldRow.employeeID;

错误消息是：

Error(1,105): PLS-00103: Encountered the symbol ";" when expecting one of the following:
( begin case declare end exception exit for goto if loop mod    null pragma raise return select update while with    <an identifier> <a double-quoted delimited-identifier> <a bind variable>
 << continue close current delete fetch lock insert open rollback savepoint set sql execute 
commit forall    merge pipe purge The symbol "exit" was substituted for ";" to continue.

编辑：这是对我的问题的澄清。我正在创建一个包含以下语句的表。每位员工都有一位经理（由FK代表）。

CREATE TABLE Employee1
(
    employeeID integer,
    firstName varchar (255),
    lastName varchar (255),
    phone integer,
    jobTitle varchar (255),
    payGrade integer,
    fk_EmployeeemployeeID integer NOT NULL,
    PRIMARY KEY(employeeID),
    FOREIGN KEY(fk_EmployeeemployeeID) REFERENCES Employee1 (employeeID)
);

然后，我想创建一个触发器，每当员工A更改其jobTitle时，它会找到所有员工将A作为其经理并将manager字段设置为null。这有什么意义吗？

Answer 1

您错过了实际触发器代码周围的BEGIN ... END块。请查看手册，其中记录了完整的语法。

下一个错误是您无法UPDATE正在更新的表。您只需将新值分配给相关列：

另一个问题是AFTER触发器无法更改任何值，您需要使用BEFORE触发器。

最后，为什么要更改DELETE触发器中的值？无论如何，该行将在删除后消失，因此无需更改该值。您可能想要使用UPDATE触发器：

CREATE OR REPLACE TRIGGER  ManagerDeleteTrigger
  BEFORE UPDATE ON employee1
  REFERENCING OLD AS OldRow
  NEW AS NewRow
  FOR EACH ROW
  WHEN (OldRow.FK_EMPLOYEEEMPLOYEEID != NewRow.FK_EMPLOYEEEMPLOYEEID)
BEGIN
  :NewRow.FK_EMPLOYEEEMPLOYEEID := null;
END;
/

Answer 2

尝试将其包装在begin和end子句中。

CREATE OR REPLACE TRIGGER  ManagerDeleteTrigger
AFTER DELETE ON employee1
REFERENCING
OLD AS OldRow
NEW AS NewRow
BEGIN
FOR EACH ROW
WHEN(OldRow.FK_EMPLOYEEEMPLOYEEID != NewRow.FK_EMPLOYEEEMPLOYEEID)
UPDATE employee1 SET FK_EMPLOYEEEMPLOYEEID = null WHERE FK_EMPLOYEEEMPLOYEEID = OldRow.employeeID
END ManagerDeleteTrigger;

Oracle中Trigger语句的编译器错误

2 个答案: