Standard SQL

The relational model and SQL and were invented and developed at IBM in the early and middle 1970s. Once IBM proved that it was possible to implement practical relational databases and that SQL was a usable language for manipulating them, other implementations of SQL were developed.

For reasons of performance or competitive advantage, or to take advantage of local hardware or software features, each SQL implementation differed in small ways from the others and from the IBM version of the language. To ensure that the differences remained small, a standards committee was formed in the early 1980s.

Committee X3H2, sponsored by the American National Standards Institute (ANSI), issued the SQL1 standard in 1986. This standard defines a core set of SQL features and the syntax of statements such as SELECT.