Structured Query Language (SQL) commands provide a standard, machine-independent relational database language.
The American National Standards Institute (ANSI) provides a basic description of the SQL language. The R:BASE/Oterro database provides a superset of this standard. The Oterro database implementation meets the requirements of ANSI 1989 Level 2 SQL with 1992 extensions.
SQL, a language developed specifically for relational databases, enables you to define, modify, and query a relational database. SQL is not a programming language, but a standard set of commands that work with a relational database.
The R:BASE/Oterro database incorporates the SQL commands into its broader range of commands. SQL commands are not treated separately in the Oterro database command because they are not special in any sense. SQL was originally defined as and must be considered an intrinsic part of a database management system.
SQL provides the following sets of commands:
Data Definition Language
Includes the commands needed to create the basic database structures—tables, columns, and views.
•ALTER TABLE (extension to SQL)
•COMMENT ON (extension to SQL)
•CREATE INDEX (extension to SQL)
•DROP INDEX (extension to SQL)
•DROP TABLE (extension to SQL)
•DROP VIEW (extension to SQL)
Data Manipulation Language
Provides modification and query capabilities.
Data Security Language Commands
Control access to the database.
•REVOKE (extension to SQL)
Transaction Processing Commands
Control when data is saved in the database, thereby allowing the restoration of data to a previous state.
•SET AUTOCOMMIT (extension to SQL)
•SET LOCK (extension to SQL)
•SET MAXTRANS (extension to SQL)
•SET TRANSACT (extension to SQL)
