Oracle trigger if updating then
For example, when a new record (representing a new worker) is added to the employees table, new records should also be created in the tables of the taxes, vacations and salaries.
Below follows a series of descriptions of how some popular DBMS support triggers.
That email contained an Oracle trigger that looked like it would be helpful, but the author of the trigger was struggling a bit with the PL/SQL code and asked for some assistance with the trigger code.
For Example: The price of a product changes constantly.
It is important to maintain the history of the prices of the products.
A trigger is a pl/sql block structure which is fired when a DML statements like Insert, Delete, Update is executed on a database table.
A trigger is triggered automatically when an associated DML statement is executed.