Learning MySQL, 2nd Edition

Chapter 3. Basic SQL

As mentioned in Chapter 2, Dr. Edgar F. Codd conceived the relational database model and its normal forms in the early 1970s. In 1974, researchers at IBM’s San Jose lab began work on a major project intended to prove the relational model’s viability, called System R. At the same time, Dr. Donald Chamberlin and his colleagues were also working to define a database language. They developed the Structured English Query Language (SEQUEL), which allowed users to query a relational database using clearly defined English-style sentences. This was later renamed Structured Query Language (SQL), for legal reasons.

The first database management systems based on SQL became available commercially by the end of the ’70s. With the growing activity surrounding the development of database languages, standardization emerged to simplify things, and the community settled on SQL. Both the American and international standards organizations (ANSI and ISO) took part in the standardization process, and in 1986 the first SQL standard was approved. The standard was later revised several times, with the names (SQL:1999, SQL:2003, SQL:2008, etc.) indicating the versions released in the corresponding years. We will use the phrase the SQL standard or standard SQL to mean the current version of the SQL standard at any time.

MySQL extends the standard SQL, providing extra features. For example, MySQL implements the STRAIGHT_JOIN, which is syntax not recognized by other DBMSs.

This ...