ORACLE觸發器實例

一、test表執行DML語句時，將相關信息記錄到日誌表test_log
--創建測試表
CREATE TABLE test ( t_id NUMBER(4), t_name VARCHAR2(20), t_age NUMBER(2), t_sex CHAR );
--創建記錄測試表
CREATE TABLE test_log ( l_user VARCHAR2(15), l_type VARCHAR2(15), l_date VARCHAR2(30) );
--創建觸發器 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觸發 v_type := 'INSERT'; DBMS_OUTPUT.PUT_LINE('記錄已經成功插入，並已記錄到日誌'); ELSIF UPDATING THEN --UPDATE觸發 v_type := 'UPDATE'; DBMS_OUTPUT.PUT_LINE('記錄已經成功更新，並已記錄到日誌'); ELSIF DELETING THEN v_type := 'DELETE'; DBMS_OUTPUT.PUT_LINE('記錄已經成功刪除，並已記錄到日誌'); END IF; INSERT INTO test_log VALUES(user,v_type, TO_CHAR(sysdate,'yyyy-mm-dd hh24:mi:ss')); END;
--下面我們來分別執行DML語句
INSERT INTO test VALUES(101,'zhao',22,'M');
UPDATE test SET t_age = 30 WHERE t_id = 101;
DELETE test WHERE t_id = 101;
--然後查看效果
SELECT * FROM test;
SELECT * FROM test_log;

二、創建觸發器，它將映射emp表中每個部門的總人數和總工資
--創建映射表
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;
--創建觸發器 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; --觸發時首先刪除映射表信息 FOR v_emp IN cur_emp LOOP --DBMS_OUTPUT.PUT_LINE(v_emp.deptno || v_emp.total_emp || v_emp.total_sal); --插入數據 INSERT INTO dept_sal VALUES(v_emp.deptno,v_emp.total_emp,v_emp.total_sal); END LOOP; END;
--對emp表進行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;

三、創建觸發器，它記錄表的刪除數據
--創建表
CREATE TABLE employee ( id VARCHAR2(4) NOT NULL, name VARCHAR2(15) NOT NULL, age NUMBER(2) NOT NULL, sex CHAR NOT NULL ); DESC employee;
--插入數據
INSERT INTO employee VALUES('e101','zhao',23,'M');
INSERT INTO employee VALUES('e102','jian',21,'F');
--創建記錄表
CREATE TABLE old_employee AS SELECT * FROM employee;
DESC old_employee;
--創建觸發器 CREATE OR REPLACE TRIGGER tig_old_emp AFTER DELETE ON employee FOR EACH ROW --語句級觸發，即每一行觸發一次 BEGIN INSERT INTO old_employee VALUES(:old.id,:old.name,:old.age,:old.sex); --:old代表舊值 END;

--下面進行測試
DELETE employee;
SELECT * FROM old_employee;

四、創建觸發器，利用視圖插入數據

--創建表
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));
--插入數據
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');
--創建視圖連接兩張表
CREATE VIEW tab_view AS
SELECT tab1.tid,tname,ttel,tadr FROM tab1,tab2 WHERE tab1.tid = tab2.tid;

--創建觸發器 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;
--現在就可以利用視圖插入數據
INSERT INTO tab_view VALUES(105,'zhaoyang','13886681288','beijing');
--查看效果
SELECT * FROM tab_view;

五、創建觸發器，比較emp表中更新的工資
CREATE OR REPLACE TRIGGER sal_emp BEFORE UPDATE ON emp FOR EACH ROW BEGIN IF :OLD.sal > :NEW.sal THEN DBMS_OUTPUT.PUT_LINE('工資減少'); ELSIF :OLD.sal < :NEW.sal THEN DBMS_OUTPUT.PUT_LINE('工資增加'); ELSE DBMS_OUTPUT.PUT_LINE('工資未作任何變動'); END IF; DBMS_OUTPUT.PUT_LINE('更新前工資 ：' || :OLD.sal); DBMS_OUTPUT.PUT_LINE('更新後工資 ：' || :NEW.sal); END;
--執行UPDATE查看效果
UPDATE emp SET sal = 3000 WHERE empno = '7788';

六、創建觸發器，將操作CREATE、DROP存儲在log_info表
--創建表
CREATE TABLE log_info ( manager_user VARCHAR2(15), manager_date VARCHAR2(15), manager_type VARCHAR2(15), obj_name VARCHAR2(15), obj_type VARCHAR2(15) );
--創建觸發器 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;
--測試語句
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;
--相關數據字典-----------------------------------------------------//
SELECT * FROM USER_TRIGGERS;
SELECT * FROM ALL_TRIGGERS;
SELECT * FROM DBA_TRIGGERS;
--必須以DBA身份登陸才能使用此數據字典
--啓用和禁用
ALTER TRIGGER trigger_name DISABLE;
ALTER TRIGGER trigger_name ENABLE;