Standardization
SQL was adopted as a standard by the American National Standards Institute (ANSI) in 1986 as SQL-86 and the International Organization for Standardization (ISO) in 1987. Nowadays the standard is subject to continuous improvement by the Joint Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee SC 32, Data management and interchange which affiliate to ISO as well as IEC. It is commonly denoted by the pattern: ISO/IEC 9075-n:yyyy Part n: title, or, as a shortcut, ISO/IEC 9075.
ISO/IEC 9075 is complemented by ISO/IEC 13249: SQL Multimedia and Application Packages (SQL/MM) which defines SQL based interfaces and packages to widely spread applications like video, audio and spatial data.
Until 1996, the National Institute of Standards and Technology (NIST) data management standards program certified SQL DBMS compliance with the SQL standard. Vendors now self-certify the compliance of their products.
The original SQL standard declared that the official pronunciation for SQL is "es queue el". Many English-speaking database professionals still use the nonstandard pronunciation /ˈsiːkwəl/ (like the word "sequel"), including Donald Chamberlin himself.
The SQL standard has gone through a number of revisions, as shown below:
| Year | Name | Alias | Comments |
|---|---|---|---|
| 1986 | SQL-86 | SQL-87 | First formalized by ANSI. |
| 1989 | SQL-89 | FIPS 127-1 | Minor revision, in which the major addition were integrity constraints. Adopted as FIPS 127-1. |
| 1992 | SQL-92 | SQL2, FIPS 127-2 | Major revision (ISO 9075), Entry Level SQL-92 adopted as FIPS 127-2. |
| 1999 | SQL:1999 | SQL3 | Added regular expression matching, recursive queries (e.g. transitive closure), triggers, support for procedural and control-of-flow statements, non-scalar types, and some object-oriented features (e.g. structured types). Support for embedding SQL in Java (SQL/OLB) and vice-versa (SQL/JRT). |
| 2003 | SQL:2003 | SQL 2003 | Introduced XML-related features (SQL/XML), window functions, standardized sequences, and columns with auto-generated values (including identity-columns). |
| 2006 | SQL:2006 | SQL 2006 | ISO/IEC 9075-14:2006 defines ways in which SQL can be used in conjunction with XML. It defines ways of importing and storing XML data in an SQL database, manipulating it within the database and publishing both XML and conventional SQL-data in XML form. In addition, it enables applications to integrate into their SQL code the use of XQuery, the XML Query Language published by the World Wide Web Consortium (W3C), to concurrently access ordinary SQL-data and XML documents. |
| 2008 | SQL:2008 | SQL 2008 | Legalizes ORDER BY outside cursor definitions. Adds INSTEAD OF triggers. Adds the TRUNCATE statement. |
| 2011 | SQL:2011 |
Interested parties may purchase SQL standards documents from ISO, IEC or ANSI. A draft of SQL:2008 is freely available as a zip archive.
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