Oracle Tigger触发器 实例
Oracle Tigger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--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_infoAFTER INSERT OR UPDATE OR DELETE ON empDECLARE?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_empAFTER 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_triggerINSTEAD OF INSERT ON tab_viewBEGIN?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_empBEFORE UPDATE ON empFOR EACH ROWBEGIN??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_infoAFTER CREATE OR DROP ON SCHEMABEGIN?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;