Sams Teach Yourself SQL in 21 Days, Fourth Edition

Using Stored Procedures, Packages, and Triggers

Using PL/SQL, you can create stored objects to eliminate having to constantly enter monotonous code. Procedures are simply blocks of code that perform some sort of specific function. Related procedures can be combined and stored together in an object called a package. A trigger is a database object that is used with other transactions. You might have a trigger on a table called ORDERS that will insert data into a HISTORY table each time the ORDERS table receives data. The basic syntax of these objects follows.

Sample Procedure

							PROCEDURE procedure_name IS
  variable1 datatype;
  ...
BEGIN
  statement1;
  ...
EXCEPTION
  when ...
END procedure_name;

One of the previous PL/SQL blocks has been converted into ...