Chapter 11. PL/SQL
There are many fine books on the market that cover the PL/SQL language in great detail.[23] Because this is a book about Oracle SQL, the focus of this chapter is the use of PL/SQL within SQL statements as well as the use of SQL within PL/SQL programs.
What Is PL/SQL?
PL/SQL is a procedural programming language from Oracle Corporation that combines the following elements:
Logical constructs such as IF-THEN-ELSE and WHILE
SQL DML statements, built-in functions, and operators
Transaction control statements such as COMMIT and ROLLBACK
Cursor control statements
Object and collection manipulation statements
Despite its humble origins as a scripting language in Version 6.0, PL/SQL became an integral part of the Oracle server with release 7.0, which correlates to release 2.0 of PL/SQL. Because release 7.0 included the ability to compile and store PL/SQL programs within the server, Oracle began using the language to provide server functionality and to assist in database installation and configuration. When release 2.1 of PL/SQL was included with the 7.1 release of the server, Oracle added a new feature of particular use to SQL programmers: the ability to call PL/SQL stored functions from SQL statements (more on this later).
Along with the array of new features made available with each release of PL/SQL, Oracle began supplying prefabricated sets of PL/SQL functionality to allow programmers to tackle more sophisticated programming tasks and to help integrate with various Oracle ...