This section is from the "Practical PostgreSQL" book, by John Worsley and Joshua Drake. Also available from Amazon: Practical PostgreSQL.
This chapter discusses the history and fundamental concepts of SQL, and forms the foundation for the next chapter, which is on applying SQL with PostgreSQL. It addresses the basics of relational databases, object-related database extensions, the structure of a SQL statement, and provides an overview of PostgreSQL-supported data types, operators and functions.
SQL, the Structured Query Language , is a mature, powerful and versatile relational query language. The history of SQL extends back to IBM research begun in 1970.
 
Continue to: