T-sql (Transact SQL) Reference (Database Engine)

Transact-SQL is central to using SQL Server. All applications that communicate with an instance of SQL Server do so by sending Transact-SQL statements to the server, regardless of the user interface of the application.

The following is a list of the kinds of applications that can generate Transact-SQL:

• General office productivity applications.
• Applications that use a graphical user interface (GUI) to let users select the tables and columns from which they want to see data.
• Applications that use general language sentences to determine what data a user wants to see.
• Line of business applications that store their data in SQL Server databases. These applications can include both applications written by vendors and applications written in-house.
• Transact-SQL scripts that are run by using utilities such as sqlcmd.
• Applications created by using development systems such as Microsoft Visual C++, Microsoft Visual Basic, or Microsoft Visual J++ that use database APIs such as ADO,
  OLE DB, and ODBC.
• Web pages that extract data from SQL Server databases.
• Distributed database systems from which data from SQL Server is replicated to various databases, or distributed queries are executed.
• Data warehouses in which data is extracted from online transaction processing (OLTP) systems and summarized for decision-support analysis.