转:Oracle触发器小结
2010-04-15 14:06 Tracy. 阅读(1511) 评论(0) 编辑 收藏 举报- --[6]// Oracle Trigger
- ---------------------------------------------------------------------------------------------//
- --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
- --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;
- DESC dept_sal;
- --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
- );
- DESC employee;
- --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;
- DESC old_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(ttel,tadr) VALUES(: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------------------------
- --创建触发器,比较emp表中更新的工资
- CREATE OR REPLACE TRIGGER sal_emp
- BEFORE UPDATE ON emp
- FOR EACH ROW
- BEGIN
-
- IF :OLD.sal > :NEW.sal THEN
- DBMS_OUTPUT.PUT_LINE('工资减少');
- ELSIF :OLD.sal < :NEW.sal THEN
- DBMS_OUTPUT.PUT_LINE('工资增加');
- ELSE
- DBMS_OUTPUT.PUT_LINE('工资未作任何变动');
- END IF;
- DBMS_OUTPUT.PUT_LINE('更新前工资 :' || :OLD.sal);
- DBMS_OUTPUT.PUT_LINE('更新后工资 :' || :NEW.sal);
- END;
- /
- --执行UPDATE查看效果
- UPDATE emp SET sal = 3000 WHERE empno = '7788';
-
- --实例6------------------------
- --创建触发器,将操作CREATE、DROP存储在log_info表
- --创建表
- 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;
- /
- --测试语句
- CREATE TABLE a(id NUMBER);
- CREATE TYPE aa AS OBJECT(id NUMBER);
- /
- DROP TABLE a;
- DROP TYPE aa;
- --查看效果
- SELECT * FROM log_info;
-
- --相关数据字典-----------------------------------------------------//
- SELECT * FROM USER_TRIGGERS;
- SELECT * FROM ALL_TRIGGERS;
- SELECT * FROM DBA_TRIGGERS; --必须以DBA身份登陆才能使用此数据字典
-
- --启用和禁用
- ALTER TRIGGER trigger_name DISABLE;
- ALTER TRIGGER trigger_name ENABLE;
- ------------------------------------------------------------------------------------------End//
本文来自博客园,作者:Tracy.,转载请注明原文链接:https://www.cnblogs.com/tracy/archive/2010/04/15/1712621.html