Structured Query Language (SQL) is a language that has been widely accepted and adopted for accessing relational databases. This language allows users to perform database operations such as reading, creating, modifying, and deleting the data. Since the summer of 1970, when Dr. E.F. Codd published the paper A Relational Model of Data for Large Shared Data Banks for the ACM journal, the language has matured comprehensively as an industry standard. With its broad range of features and easy adaptation to enterprise environments, the SQL language has been typically regarded as the most reliable language for interacting with relational databases.
PL/SQL was developed in 1991 by Oracle Corporation as a procedural language extension to SQL. Its ability to integrate seamlessly with SQL makes it a powerful language to construct the data access layer and the rich procedural extensions help in translating business logic within the Oracle Database. This first chapter introduces you to the PL/SQL language and refreshes some of the key programming concepts. The chapter is outlined as follows:
Introduction to PL/SQL
Recapitulate procedures, functions, packages, and cursors
Exception handling
Object dependencies
Major Oracle supplied packages
Oracle Development tools—SQL Developer and SQL*Plus