C. J. Date is an independent author, lecturer, researcher, and consultant specializing in relational database systems, a field he helped pioneer. Among other projects, he was involved in technical planning for the IBM products SQL/DS and DB2. He is best known for his books, in particular, An Introduction to Database Systems (7th edition, Addison-Wesley, 2000), the standard text in the field, which has sold well over half a million copies worldwide. Mr. Date is widely acknowledged for his ability to explain complex technical material in a clear and understandable fashion.
Hugh Darwen has been involved in software development since 1967 as an employee of IBM United Kingdom, Ltd. He has been active in the relational database arena since 1978. He was one of the chief architects and developers of an IBM relational product called Business System 12, a product that faithfully embraced the principles of the relational model. He has been an active participant in the development of SQL international standards since 1988.