Transact-SQL Extensions

Transact-SQL enhances the power of SQL, and minimizes the occasions on which users must resort to a programming language to accomplish a desired task. Transact-SQL capabilities go beyond the ISO standards and the many commercial versions of SQL.

See, Reference Manual: Commands for the Transact-SQL extensions for each command.

• compute Clause
  The Transact-SQL compute clause extension is used with the row aggregate functions sum, max, min, avg, count, and count_big to calculate summary values.
• Control-of-Flow Language
  Transact-SQL provides control-of-flow language that you can use as part of any SQL statement or batch.
• Stored Procedures
  One of the most important Transact-SQL extensions is the ability to create stored procedures. A stored procedure is a collection of SQL statements and optional control-of-flow statements stored under a name.
• Extended Stored Procedures
  An extended stored procedure (ESP) uses the same interface as a stored procedure, but instead of containing SQL statements and control-of-flow statements, it executes procedural language code that has been compiled into a dynamic link library (DLL).
• Triggers
  A trigger is a stored procedure that instructs the system to take one or more actions when a specific change is attempted. By preventing incorrect, unauthorized, or inconsistent changes to data, triggers help maintain the integrity of a database.
• Defaults and Rules
  Transact-SQL provides keywords for maintaining entity integrity, which ensures that a value is supplied for every column that requires one, and domain integrity, which ensures that each value in a column belongs to the set of legal values for that column.
• Error Handling and set Options
  Transact-SQL error-handling techniques include capturing return status from stored procedures, defining customized return values from stored procedures, passing parameters from a procedure to its caller, and retrieving reports from global variables.
• Additional SAP ASE Extensions to SQL
  SAP ASE includes additional features of Transact-SQL.