ORACLE触发器实例

朴灿烈づ我的快乐病毒、 2022-06-09 03:25 259阅读 0赞

## ORACLE触发器实例 ##

**--实例1------------------------**  
\--创建触发器，当用户对test表执行DML语句时，将相关信息记录到日志表  
\--创建测试表  
CREATE TABLE test  
(  
t\_id NUMBER(4),  
t\_name VARCHAR2(20),  
t\_age NUMBER(2),  
t\_sex CHAR  
);  
\--创建记录测试表  
CREATE TABLE test\_log  
(  
l\_user VARCHAR2(15),  
l\_type VARCHAR2(15),  
l\_date VARCHAR2(30)  
);  
\--创建触发器  
CREATE OR REPLACE TRIGGER test\_trigger  
AFTER DELETE OR INSERT OR UPDATE ON test  
DECLARE  
v\_type test\_log.l\_type%TYPE;  
BEGIN  
IF INSERTING THEN --INSERT触发  
v\_type := 'INSERT';  
DBMS\_OUTPUT.PUT\_LINE('记录已经成功插入，并已记录到日志');  
ELSIF UPDATING THEN --UPDATE触发  
v\_type := 'UPDATE';  
DBMS\_OUTPUT.PUT\_LINE('记录已经成功更新，并已记录到日志');  
ELSIF DELETING THEN  
v\_type := 'DELETE';  
DBMS\_OUTPUT.PUT\_LINE('记录已经成功删除，并已记录到日志');  
END IF;  
INSERT INTO test\_log VALUES(user,v\_type,  
TO\_CHAR(sysdate,'yyyy-mm-dd hh24:mi:ss'));  
END;

\--下面我们来分别执行DML语句  
INSERT INTO test VALUES(101,'zhao',22,'M');  
UPDATE test SET t\_age = 30 WHERE t\_id = 101;  
DELETE test WHERE t\_id = 101;  
\--然后查看效果  
SELECT \* FROM test;  
SELECT \* FROM test\_log;

**--实例2------------------------**  
\--创建触发器，它将映射emp表中每个部门的总人数和总工资

\--员工表

create table emp

(  
DEPTNO VARCHAR2(20),  
EMPNO VARCHAR2(20),  
SAL NUMBER(4)  
)  
\--创建映射表  
CREATE TABLE dept\_sal  
AS  
SELECT deptno,COUNT(empno) AS total\_emp,SUM(sal) AS total\_sal FROM emp GROUP BY deptno;  
\--创建触发器  
CREATE OR REPLACE TRIGGER emp\_info  
AFTER INSERT OR UPDATE OR DELETE ON emp  
DECLARE  
CURSOR cur\_emp IS  
SELECT deptno,COUNT(empno) AS total\_emp,SUM(sal) AS total\_sal FROM emp GROUP BY deptno;  
BEGIN  
DELETE dept\_sal; --触发时首先删除映射表信息  
FOR v\_emp IN cur\_emp LOOP  
\--DBMS\_OUTPUT.PUT\_LINE(v\_emp.deptno || v\_emp.total\_emp || v\_emp.total\_sal);  
\--插入数据  
INSERT INTO dept\_sal  
VALUES(v\_emp.deptno,v\_emp.total\_emp,v\_emp.total\_sal);  
END LOOP;  
END;  
\--对emp表进行DML操作  
INSERT INTO emp(empno,deptno,sal) VALUES('123','10',10000);  
SELECT \* FROM dept\_sal;  
DELETE EMP WHERE empno=123;  
SELECT \* FROM dept\_sal;

**--实例3------------------------**  
\--创建触发器，它记录表的删除数据  
\--创建表  
CREATE TABLE employee  
(

id VARCHAR2(4) NOT NULL,  
name VARCHAR2(15) NOT NULL,  
age NUMBER(2) NOT NULL,  
sex CHAR NOT NULL  
);

\--插入数据  
INSERT INTO employee VALUES('e101','zhao',23,'M');  
INSERT INTO employee VALUES('e102','jian',21,'F');  
\--创建记录表  
CREATE TABLE old\_employee AS  
SELECT \* FROM employee;  
\--创建触发器  
CREATE OR REPLACE TRIGGER tig\_old\_emp  
AFTER DELETE ON employee --  
FOR EACH ROW --语句级触发，即每一行触发一次  
BEGIN  
INSERT INTO old\_employee  
VALUES(:old.id,:old.name,:old.age,:old.sex); --:old代表旧值  
END;  
  
\--下面进行测试  
DELETE employee;  
SELECT \* FROM old\_employee;

**--实例4------------------------**

\--创建触发器，利用视图插入数据  
\--创建表

CREATE TABLE tab1 (tid NUMBER(4) PRIMARY KEY,tname VARCHAR2(20),tage NUMBER(2));  
CREATE TABLE tab2 (tid NUMBER(4),ttel VARCHAR2(15),tadr VARCHAR2(30));  
\--插入数据  
INSERT INTO tab1 VALUES(101,'zhao',22);  
INSERT INTO tab1 VALUES(102,'yang',20);  
INSERT INTO tab2 VALUES(101,'13761512841','AnHuiSuZhou');  
INSERT INTO tab2 VALUES(102,'13563258514','AnHuiSuZhou');  
\--创建视图连接两张表  
CREATE VIEW tab\_view AS  
SELECT tab1.tid,tname,ttel,tadr FROM tab1,tab2  
WHERE tab1.tid = tab2.tid;  
\--创建触发器  
CREATE OR REPLACE TRIGGER tab\_trigger

INSTEAD OF INSERT ON tab\_view  
BEGIN  
INSERT INTO tab1(tid,tname) VALUES(:new.tid,:new.tname);  
INSERT INTO tab2(tid,ttel,tadr) VALUES(:new.tid,:new.ttel,:new.tadr);  
END;

\--现在就可以利用视图插入数据  
INSERT INTO tab\_view VALUES(105,'zhaoyang','13886681288','beijing');  
\--查看效果  
SELECT \* FROM tab\_view;

**--实例5------------------------**

根据工资的改动提示涨工资了还是降工资了。

创建触发器：  
CREATE OR REPLACE TRIGGER sal\_emp  
BEFORE UPDATE ON z\_test  
FOR EACH ROW  
BEGIN  
IF :OLD.sal > :NEW.sal THEN  
DBMS\_OUTPUT.PUT\_LINE('降工资了');  
ELSIF :OLD.sal < :NEW.sal THEN  
DBMS\_OUTPUT.PUT\_LINE('加工资了');  
ELSE  
DBMS\_OUTPUT.PUT\_LINE('工资没有变');  
END IF;  
DBMS\_OUTPUT.PUT\_LINE('以前工资为:' || :OLD.sal);  
DBMS\_OUTPUT.PUT\_LINE('现在工资为' || :NEW.sal);  
END;  
在测试窗口中执行：

UPDATE emp SET sal = 3000 WHERE empno = '7788';

commit;

测试窗口如下图：

![1f84a41f95fb4d49314e150f.jpg][]

查看DBMS输入：

![1806aade065a561795ee3715.jpg][]  
**--实例6-----------------------**

简单记录操作日志

日志记录表：

CREATE TABLE log\_info  
(  
manager\_user VARCHAR2(15),  
manager\_date VARCHAR2(15),  
manager\_type VARCHAR2(15),  
obj\_name VARCHAR2(15),  
obj\_type VARCHAR2(15)  
);

创建触发器：

CREATE OR REPLACE TRIGGER trig\_log\_info  
AFTER CREATE OR DROP ON SCHEMA  
BEGIN  
INSERT INTO log\_info  
VALUES(USER,SYSDATE,SYS.DICTIONARY\_OBJ\_NAME,SYS.DICTIONARY\_OBJ\_OWNER,  
SYS.DICTIONARY\_OBJ\_TYPE);  
END;

测试：

CREATE TABLE a(id NUMBER);  
CREATE TYPE aa AS OBJECT(id NUMBER);

查看日志：

SELECT \* FROM log\_info;

**--其他-----------------------**

**查询有哪些触发器**

**SELECT \* FROM USER\_TRIGGERS;  
SELECT \* FROM ALL\_TRIGGERS;  
SELECT \* FROM DBA\_TRIGGERS;**

**修改触发器是否起效：**

**ALTER TRIGGER trigger\_name DISABLE;  
ALTER TRIGGER trigger\_name ENABLE;**

[1f84a41f95fb4d49314e150f.jpg]: /images/20220609/c00d9a1e0ab64f2c83cccfe0e6c64471.png
[1806aade065a561795ee3715.jpg]: /images/20220609/666f2fcc0fe54e92a9c37972bae0279b.png