What is the history of Structured English Query Language and what is its relationship to SQL?
In 1970 Dr. E. F. Codd published his paper,”A Relational Model of Data for Large Shared Data Banks”. This became the foundation for the relational database system. This paper described a new way to structure data within a database, and led to the relational database systems we use today. While Dr. Codd’s paper defined the structure, his colleagues Donald D. Chamberlin and Raymond F. Boyce at IBM had been developing a query language known as SQUARE (Specifying Queries As Relational Expressions), which used set theory and predicate mathematics to select data from the database. This language had a terse mathematical syntax, but became the proving ground for concepts which are important to database manipulation. By 1974, Chamberlin and Boyce published “SEQUEL: A Structured English Query Language” which detailed their refinements to SQUARE and introduced us to the data retrieval aspects of SEQUEL. This new SEQUEL language was as powerful as SQUARE, but Chamberlin and Boyce “kept in mind the
