Using AFTER INSERT Trigger in Oracle

This Oracle tutorial explains how to create an AFTER INSERT Trigger in Oracle with syntax and examples.

Description

An AFTER INSERT Trigger capacity that Oracle will fire this trigger after the INSERT operation is executed.

Syntax

The syntax to create an AFTER INSERT Trigger in Oracle/PLSQL is:

CREATE [ OR REPLACE ] TRIGGER trigger_name
AFTER INSERT
   ON table_name
   [ FOR EACH ROW ]

DECLARE
   -- variable declarations

BEGIN
   -- trigger code

EXCEPTION
   WHEN ...
   -- exception handling

END;

Parameters or Arguments

OR REPLACE Optional. If specified, it lets in you to re-create the trigger is it already exists so that you can change the trigger definition without issuing a DROP TRIGGER statement. trigger_name The title of the set off to create. AFTER INSERT It suggests that the trigger will furnace after the INSERT operation is executed. table_name The title of the desk that the trigger is created on.

Restrictions

You can not create an AFTER set off on a view. You can not replace the :NEW values. You can not replace the :OLD values.

Note

See additionally how to create AFTER DELETE, AFTER UPDATE, BEFORE DELETE, BEFORE INSERT, and BEFORE UPDATE triggers. See additionally how to drop a trigger.

Example

Let’s seem to be at an example of how to create an AFTER INSERT set off using the CREATE TRIGGER statement.

If you had a table created as follows:

CREATE TABLE orders
( order_id number(5),
  quantity number(4),
  cost_per_item number(6,2),
  total_cost number(8,2)
);

We ought to then use the CREATE TRIGGER statement to create an AFTER INSERT set off as follows:

TIP: When the usage of SQLPlus, you want to enter reduce on a new line after the trigger. Otherwise, the script won’t execute.

CREATE OR REPLACE TRIGGER orders_after_insert
AFTER INSERT
   ON orders
   FOR EACH ROW

DECLARE
   v_username varchar2(10);

BEGIN

   -- Find username of person performing the INSERT into the table
   SELECT user INTO v_username
   FROM dual;

   -- Insert record into audit table
   INSERT INTO orders_audit
   ( order_id,
     quantity,
     cost_per_item,
     total_cost,
     username )
   VALUES
   ( :new.order_id,
     :new.quantity,
     :new.cost_per_item,
     :new.total_cost,
     v_username );

END;

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