Sams Teach Yourself SQL in 21 Days, Fourth Edition

Introducing PL/SQL

One way to introduce PL/SQL is to begin by describing standard Structured Query Language, or SQL. SQL is the language that enables relational database users to communicate with the database in a straightforward manner. You can use SQL commands to query the database and modify tables within the database.

When you write a SQL statement, you are telling the database what you want to do, not how to do it. The query optimizer decides the most efficient way to execute your statement. If you send a series of SQL statements to the server in standard SQL, the server executes them one at a time in chronological order.

PL/SQL is Oracle's procedural language; it comprises the standard language of SQL and a wide array of commands that enable ...