DataBase System 多 History of SQL H IBM Sequel (specifying QUeries As Relational Expression, 1972)language developed as part of System R project at the IBM San Jose research lab H SEQUEL (Structured English QUEry language, 1974) Renamed SQL( Structured Query Language, 1976) E ANSI and ISO standard SQL SQL-86, SQL-89(SQL1) >SQL-92 (SQL2 SQL: 1999(SQL3) SOL:2003 A Commercial systems offer most, if not all, sQL-92 features plus varying feature sets from later standards and special proprietary features Haichang Gao, Software School, Xidian UniversityDataBase System Haichang Gao , Software School , Xidian University 5 History of SQL  IBM Sequel (Specifying QUeries As Relational Expression, 1972) language developed as part of System R project at the IBM San Jose Research Lab  SEQUEL (Structured English QUEry Language,1974) Renamed SQL (Structured Query Language, 1976)  ANSI and ISO standard SQL: ➢ SQL-86, SQL-89 (SQL1) ➢ SQL-92 (SQL2) ➢ SQL:1999 (SQL3) ➢ SQL:2003  Commercial systems offer most, if not all, SQL-92 features, plus varying feature sets from later standards and special proprietary features