Donald Chamberlin and Raymond Boyce developed SQL at IBM for working with relational databases.
The language began as SEQUEL, short for Structured English Query Language, during the 1970s. It was influenced by Edgar F. Codd’s relational model, which represented data in tables and described operations over those relations. The name was later shortened to SQL because of a trademark issue involving “SEQUEL.”
SQL lets users define database structures, query data, and modify records. It is declarative: users generally describe the desired result rather than specify every procedural step used to calculate it.
SQL is distinct from PL/SQL, which Oracle developed as a procedural extension, and from GraphQL, a later query language for APIs. SQL was standardized by ANSI in 1986 and by ISO in 1987, although database systems still differ in their dialects and extensions.