Discover the world with our lifehacks

What are the 12 types of triggers in Oracle?

What are the 12 types of triggers in Oracle?

Triggers on System Events and User Events

  • System events. Database startup and shutdown. Data Guard role transitions. Server error message events.
  • User events. User logon and logoff. DDL statements ( CREATE , ALTER , and DROP ) DML statements ( INSERT , DELETE , and UPDATE )

How do you stop a trigger in Oracle?

To disable a trigger, you use the ALTER TRIGGER DISABLE statement:

  1. ALTER TRIGGER trigger_name DISABLE;
  2. ALTER TRIGGER customers_audit_trg DISABLE;

Which clause is used to restrict a row level trigger?

WHEN (condition) – This clause is valid only for row level triggers. The trigger is fired only for rows that satisfy the condition specified.

Which clause is used to specify triggering restrictions?

All triggers defined for a specific table can be enabled with one statement using the ALTER TABLE statement with the ENABLE clause with the ALL TRIGGERS option.

How many triggers are possible per table?

There are 12 types of triggers can exist in a table in Oracle: 3 before statement, 3 after statement, 3 before each row and 3 after each row. On a single table you can define as many triggers as you need.

Can one trigger initiate another trigger?

Both DML and DDL triggers are nested when a trigger performs an action that initiates another trigger. These actions can initiate other triggers, and so on. DML and DDL triggers can be nested up to 32 levels. You can control whether AFTER triggers can be nested through the nested triggers server configuration option.

Can we disable a trigger if yes how?

The trigger still exists as an object in the current database. However, the trigger does not fire when any Transact-SQL statements on which it was programmed are executed. Triggers can be re-enabled by using ENABLE TRIGGER. DML triggers defined on tables can be also be disabled or enabled by using ALTER TABLE.

How do you stop a trigger in SQL?

To disable and enable a DML trigger Expand the database that you want, expand Tables, and then expand the table that contains the trigger that you want to disable. Expand Triggers, right-click the trigger to disable, and then click Disable.

What is difference between row level and statement level trigger?

Row level triggers executes once for each and every row in the transaction. Statement level triggers executes only once for each single transaction.

Can we have two triggers on same table in Oracle?

Oracle allows more than one trigger to be created for the same timing point, but it has never guaranteed the execution order of those triggers.

Which operation are not specified in triggers?

Explanation: Triggers are not possible for create, drop.

What is the maximum size of a trigger?

The size of the trigger cannot exceed 32K. If the logic for your trigger requires much more than 60 lines of PL/SQL source code, then put most of the source code in a stored subprogram and invoke the subprogram from the trigger.

Can a trigger prevent an insert operation from completing?

The only way for a trigger on a table to prevent an INSERT operation from completing is to throw an error. Create an instead of trigger on that view that only does an INSERT on the table if you want the row to be persisted.

How to create a trigger in the disabled state in Oracle?

To create a trigger in the disabled state, you use the CREATE TRIGGER statement with the DISABLE option: This example creates a trigger on the table customers in the disabled state: In this tutorial, you have learned how to use disable a trigger or all triggers of a table in the Oracle Database.

How do I disable a trigger in Salesforce?

First, right-click the trigger name and select Disableā€¦ menu item. Second, click the Apply button in the dialog to disable the trigger. Third, click the OK button in the confirmation dialog to acknowledge that the trigger has been disabled.

How do I disable all triggers associated with a table?

You can disable all triggers associated with a table at the same time using the ALTER TABLE statement with the DISABLE ALL TRIGGERS option. For example, to disable all triggers defined for the inventory table, enter the following statement: