ORACLE 的触发器类型有哪些,ORACLE触发器类型

ORACLE触发器类型

1.DML触发器

由对表的INSERT,DELETE,UPDATE激发

CREATE OR REPLACE TRIGGER trigger_name

AFTER                                    — TIMING :BEFORE OR AFTER

DELETE OR INSERT OR UPDATE ON table_name — STATEMENT

–REFERENCING :new a :old b

FOR EACH ROW                             — LEVEL

BEGIN

–PL/SQL

IF INSERTING THEN

insert into AUDIT_STUDENT

values

(sysdate, :new.id, :new.name, ‘INSERT’);

ELSIF DELETING THEN

insert into AUDIT_STUDENT

values

(sysdate, :old.id, :old.name, ‘DELETE’);

ELSE

insert into AUDIT_STUDENT

values

(sysdate, :old.id, :old.name, ‘UPDATE’);

END IF;

END;

/

/*DML触发器执行顺序

a.BEFORE语句级

b.BEFORE行级

c.AFTER行级

d.AFTER语句级

*/

2.INSTEAD OF触发器

代替直接对视图的INSERT,DELETE,UPDATE操作

CREATE OR REPLACE TRIGGER VW_STU_COURSE_INSERT

INSTEAD OF INSERT ON VW_STU_COURSE

FOR EACH ROW

DECLARE

rowcnt number;

BEGIN

INSERT INTO stu_info(id,name)

values(:new.id,:new.name);

insert into course_info(course_no,course_name)

values(:new.course_no,:new.course_name);

END;

/

3.系统触发器

a.DDL事件(CREATE,ALTER,DROP语句),需要有ADMISTRATER,DATABASE,TRIGGER特权

b.数据库事件

服务器启动,关闭

用户登录,注销

服务器错误等

CREATE OR REPLACE TRIGGER LogUser2Connects

AFTER LOGON ON DATABASE

BEGIN

INSERT INTO logon_record

values(sysdate,ora_login_user);

END;

/

–Enabling And Disabling Triggers

–Enabling Triggers

ALTER TRIGGER REORDER ENABLE;

ALTER TABLE INVENTORY ENABLE ALL TRIGGERS;

–Enabling Triggers

ALTER TRIGGER REORDER DISABLING;

ALTER TABLE INVENTORY DISABLING ALL TRIGGERS;

–View Of TriggersUSER_TRIGGERSALL_TRIGGERSDBA_TRIGGERS