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Can a SQL statement cause a database trigger?
SQL statements within an Oracle Forms application, as with any database application, can implicitly cause the firing of any associated database trigger. For more information about Oracle Forms and Oracle Forms triggers, see theOracle Forms User’s Guide. Triggers vs. Declarative Integrity Constraints
What are the problems with triggers in Oracle?
The next implementation problem with triggers stems from the fact that developers often do not understand all the nuances of concurrency controls and isolation levels in the database. One of Oracle Database’s greatest features is that reads do not block writes and writes do not block reads.
Can you have multiple triggers for the same table?
You can have multiple triggers of the same type for the same statement for any given table. For example, you can have two BEFORE statement triggers for UPDATE statements on the employees table. Multiple triggers of the same type permit modular installation of applications that have triggers on the same tables.
How are database triggers similar to stored procedures?
These procedures are called database triggers. Triggers are similar to stored procedures, discussed in Chapter 14, “Procedures and Packages”. A trigger can include SQL and PL/SQL statements to execute as a unit and can invoke stored procedures. However, procedures and triggers differ in the way that they are invoked.
When to use Cascading triggers in a database?
Cascading Triggers While triggers are useful for customizing a database, you should only use triggers when necessary. The excessive use of triggers can result in complex interdependences, which may be difficult to maintain in a large application. Database Triggers vs. Oracle Forms Triggers
What are the benefits of triggers in databases?
Triggers give you control just before data is changed and just after the data is changed. This allows for: Auditing as mentioned before. Validation and business security checking if so is desired. Because of this type of control, you can do tasks such as column formatting before and after inserts into database.
When to use SQL triggers instead of DML triggers?
DDL Triggers and DML Triggers (of types: INSTEAD OF, For, and AFTER) Non-Trigger Stored procedures can reference any type of object, however, to reference a view, you must use INSTEAD OF triggers. In SQLServer, you can have any number on non-trigger stored procedures but only 1 INSTEAD OF trigger per table.