SQL:2011

SQL:2011 or ISO/IEC 9075:2011 (under the general title "Information technology – Database languages – SQL") is the seventh revision of the ISO (1987) and ANSI (1986) standard for the SQL database query language. It was formally adopted in December 2011. The standard consists of 9 parts which are described in detail in SQL. The next version is SQL:2016.

==New features== One of the main new features is improved support for temporal databases. Language enhancements for temporal data definition and manipulation include: Time period definitions use two standard table columns as the start and end of a named time period, with closed set-open set semantics. This provides compatibility with existing data models, application code, and tools Definition of application time period tables (elsewhere called valid time tables), using the annotation Update and deletion of application time rows with automatic time period splitting Temporal primary keys incorporating application time periods with optional non-overlapping constraints via the clause Temporal referential integrity constraints for application time tables Application time tables are queried using regular query syntax or using new temporal predicates for time periods including , , , , , and (which are modified versions of Allen’s interval relations) Definition of system-versioned tables (elsewhere called transaction time tables), using the annotation and modifier. System time periods are maintained automatically. Constraints for system-versioned tables are not required to be temporal and are only enforced on current rows Syntax for time-sliced and sequenced queries on system time tables via the and clauses Application time and system versioning can be used together to provide bitemporal tables