Use of triggers in Oracle (based on system events and user events)

ReateOr Replace TriggerTr_insert_emp BeforeInsert OnEmpForEach row Begin Insert IntoAValues(: New. empno,: new. ename,: new. job,: new. mgr,: new. hiredate,: new. sal,: new. comm,: new. deptno ); End; Insert IntoEmpValues(1,'A','Soft', 4, to_date ('2017-09-12','Yyyy-MM-dd'), 1, 1, 20 ); Select*FromA;

: New. data,: old. data

Triggers based on system events and user events,

For example, when the database is started

Create Or Replace TriggerTr_db_log AfterStartup On Database Begin -- Do what you want to do! End;

And you can use before shutdown.

When the table is cleared, the trigger
Create or replace trigger tr_truncate_table
After truncate
Begin
Insert into A_table values (ora_dict_obj_name, user, sysdate );
-- Ora_dict_obj_name specifies the name of the object to be deleted.
End;

Disable a trigger
Alter tirgger tr_name disable;

Enable trigger
Alter trigger tr_name enable;