• In 1970 at the IBM research lab the new language had been developed to access data from the database system which are base on the relation model.
  • This language was usually known as Structured English Query Language (SEQUEL).
  • Later on stage the word English was dropped and known as ‘SQL’ for Structured Query Language.
  • This language became standard as an interface for accessing data from the RDBMS system.
  • ANSI & ISO also accepted SQL as the standard interface for relational database systems
  • It contains components like DDL (Data Dictionary Language), DML (Data Definition Language), and DQL (Data Query Language)