Trigger in Orcale Database

What is Trigger in Orcale Database

Oracle allows you to define procedures that are implicitly executed when an DML statement  (insert ,update,delete) is issued against the associated table. These procedures are called database triggers.

 A database trigger is procedural code that is automatically executed in response to certain events on a particular table or view in a database.

For example-

create a table marks 

create table marks(rollno int primary key, name varchar(20), phy int, chem int, math int);

again another  create table  which name is backupmarks

create table backupmarks (rollno int primary key, name varchar(20), phy int, chem int, math int);

create trigger

create trigger backuptrigger

after insert on marks for each row

begin

insert into backupmarks values(:new.rollno,:new.name,:new.phy,:new.chem,:new.math);

end;

after creating trigger you  insert  data  in table marks

insert into marks values(1,'arvind',78,67,89);

 Data is  inserting only marks table but you can see automatically executed in response to certain events on a particular  table backupmarks.                                                       

you can cheack  results

select*from marks;

select*from backupmarks;

after running this  query  you got same resuls  This  is Trigger  Concepts

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