What are different types of triggers?

What are the types of triggers?

• DDL Trigger.
• DML Trigger.
• Logon Trigger.

How do you run a trigger?

To invoke a trigger, a user must have the privilege to execute the data change statement associated with the trigger event. Similarly, to successfully invoke an SQL routine or dynamic compound statement a user must have the EXECUTE privilege on the routine.

What are trigger concepts?

A trigger is a special type of stored procedure that automatically runs when an event occurs in the database server. DML triggers run when a user tries to modify data through a data manipulation language (DML) event. DML events are INSERT, UPDATE, or DELETE statements on a table or view.

What is the purpose of triggers?

The main purpose of triggers is to automate execution of code when an event occurs. In other words, if you need a certain piece of code to always be executed in response to an event, the best option is to use triggers.

What is an instead of trigger?

An INSTEAD OF trigger is a trigger that allows you to update data in tables via their view which cannot be modified directly through DML statements. When you issue a DML statement such as INSERT , UPDATE , or DELETE to a non-updatable view, Oracle will issue an error.

Which trigger is executed first?

First : Trigger is fired first. Last : Trigger is fired last.

What is a trigger in Oracle?

Oracle Trigger. In Oracle, you can define procedures that are implicitly executed when an INSERT, UPDATE or DELETE statement is issued against the associated table. These procedures are called database triggers.

What are triggers?

You will also learn about different characters of triggers and their usage in the database. A trigger is a named PL/SQL block stored in the Oracle Database and executed automatically when a triggering event takes place. The event can be any of the following:

What is a DDL trigger in Oracle?

A data definition language (DDL) statement executes e.g., CREATE or ALTER statement. These triggers are often used for auditing purposes to record changes of the schema. A system event such as startup or shutdown of the Oracle Database.

How to create a custom database trigger?

DATABASE Trigger: It fires when the database event is specified (LOGON/LOGOFF/STARTUP/SHUTDOWN) So each trigger is the combination of above parameters. Below is the syntax for creating a trigger. CREATE [ OR REPLACE ] TRIGGER [BEFORE | AFTER | INSTEAD OF ] [INSERT | UPDATE | DELETE……]