Answer / madhuri

Triggers are basically PL/SQL procedures that are associated
with tables, and are fired whenever a certain modification
(event) occurs. The modification statements may include
INSERT, UPDATE, and DELETE.

The general structure of triggers is:
CREATE [OR REPLACE]TRIGGER trigger_name
BEFORE/AFTER
INSERT/UPDATE/DELETE ON tablename
[FOR EACH ROW [WHEN (condition)]]
BEGIN
...
END;

Answer / anil_abbireddy

Trigger is a named Pl/Sql block associated with a table and
executed implicitly by the oracle when the DML operations
are performed against that table.

Answer / vijay bhaskar reddy

trigger is a named pl/sql block and it is fired when ever
an event is occured....

Answer / ramesh yadav

Trigger is named as a database object. That's associated
with particular table event occur for the table.

Answer / anbu

Trigger is a mecanism to execute your condition at anywhere
at anytime during the execution time of your programme.

Answer / kiran

Trigger is a special type of stored procedure which is
implicitely executed when an insert , update or delete
happens on the data.
We dnt have to call trigger explicitely.
For applying some business rules we can fire trigger at
specific type.
Suppose i want a log when user inserts data on a particular
table i can use trigger.

2 types of trigger
1) DML Trigger - Applies on data -
- Instead of and After Trigger
2)DDL Trigger - Applies on database structure - on table or
database - these triggers came with sql server 2005.

Before sql server 2005 we were having only DML Triggers.

Answer / veera

Trigger is an database object and Associated with table or View. Whenever perform operations(DML,select)on that table or view trigger fire implicitly and executes set of PL/SQL statements.

Answer / shaikkhalandar407@gmail.com

Triggers are stored programs that are fired automatically when some events occur. The code to be fired can be defined as per the requirement.

Oracle has also provided the facility to mention the event upon which the trigger needs to be fire and the timing of the execution

Benefits of Triggers :
Generating some derived column values automatically
Enforcing referential integrity
Event logging and storing information on table access
Auditing
Synchronous replication of tables
Imposing security authorizations
Preventing invalid transactions
Types of Triggers in Oracle
Triggers can be classified based on the following parameters.

Classification based on the timing
BEFORE Trigger: It fires before the specified event has occurred.
AFTER Trigger: It fires after the specified event has occurred.
INSTEAD OF Trigger: A special type. You will learn more about the further topics. (only for DML )
Classification based on the level
STATEMENT level Trigger: It fires one time for the specified event statement.
ROW level Trigger: It fires for each record that got affected in the specified event. (only for DML)
Classification based on the Event
DML Trigger: It fires when the DML event is specified (INSERT/UPDATE/DELETE)
DDL Trigger: It fires when the DDL event is specified (CREATE/ALTER)
DATABASE Trigger: It fires when the database event is specified (LOGON/LOGOFF/STARTUP/SHUTDOWN)

Answer / salim

Trigger is a 4th named block in pl/sql associated with a
table.

Answer / akki julakanti

Trigger is an event that fires when a specicified event is
occured.

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