The publication of Codd's rules resulted in a considerable amount of relational database research done in the early 1970s. By 1974, IBM had surfaced with a prototype of a relational database called System/R. The System/R project ended in 1979, but two significant accomplishments are accredited to that project. The relational data model's viability was sufficiently proven to the world and the project included significant work on a database query language. 

By the end of the System/R project, IBM had implemented a language that supported System/R's multi-table queries and multiple-user access called the Structured English Query Language (SEQUEL). The name later was shortened to Structured Query Language (SQL). Today, we still pronounce the abbreviation as "sequel" because of these early roots.

A group of engineers watching the System/R project realized relational databases' potential and formed a company named Relational Software, Inc. In 1979, they produced the first commercially available relational database management system and implemented SQL as its query language. They called the product Oracle.

As a language, SQL did have its competitors – most notable was QUEL, used by the Ingres RDBMS. During the early 1980's, Oracle and Ingres's provider, Relational Technology, Inc., slugged it out on the commercial market before Ingres lost in 1986 and adopted SQL as its query language. Of course, IBM followed up its System/R research project with its own product, SQL/Data System (SQL/DS) and later Database 2 (DB2). With IBM's weight behind the product, their version of SQL became the de facto standard.

Since then, many relational database management systems have come to market – all supporting SQL as their primary language. Once it became apparent that relational databases were here to stay, ANSI began work on creating a standard definition. Today's SQL standard is based mostly on IBM's implementation, with a considerable amount of additions. In fact, the SQL2 standard contains definitions of features that have yet to implemented by any of the major vendors.

A second standard for SQL sprung up in Europe from X/OPEN, a group assembling standards for a UNIX-based portable application environment. X/OPEN standards play a major role in the European market; unfortunately, several features differ between the X/OPEN and the ANSI/ISO standards. The examples and discussions in this newsletter will adhere to the ANSI/ISO standards. The major commercial databases all adhere to this standard, including Microsoft SQL Server 7, Oracle 8, Informix, Sybase, and, of course, IBM DB2.

Next Week: A quick introduction to SQL