plsql triggers

Trigger
Triggering SQL statement : SQL DML (INSERT, UPDATE and DELETE) statement that execute and implicitly called trigger to execute.
Trigger Action : When the triggering SQL statement is execute, trigger automatically call and PL/SQL trigger block execute.
Trigger Restriction : We can specify the condition inside trigger to when trigger is fire.


Type of Triggers

BEFORE Trigger :

BEFORE trigger execute before the triggering DML statement (INSERT, UPDATE, DELETE) execute. Triggering SQL statement is may or may not execute, depending on the BEFORE trigger conditions block.

AFTER Trigger :

AFTER trigger execute after the triggering DML statement (INSERT, UPDATE, DELETE) executed. Triggering SQL statement is execute as soon as followed by the code of trigger before performing Database operation.

ROW Trigger :

ROW trigger fire for each and every record which are performing INSERT, UPDATE, DELETE from the database table. If row deleting is define as trigger event, when trigger file, deletes the five rows each times from the table.

Statement Trigger :

Statement trigger fire only once for each statement. If row deleting is define as trigger event, when trigger file, deletes the five rows at once from the table.

Combination Trigger :

Combination trigger are combination of two trigger type,

Before Statement Trigger :

Trigger fire only once for each statement before the triggering DML statement.

Before Row Trigger :

Trigger fire for each and every record before the triggering DML statement.

After Statement Trigger :

Trigger fire only once for each statement after the triggering DML statement executing.

After Row Trigger :

Trigger fire for each and every record after the triggering DML statement executing.