Using Cursors (ODBC)

ODBC supports a cursor model that allows:

• Several types of cursors.

• Scrolling and positioning within a cursor.

• Several concurrency options.

• Positioned updates.

ODBC applications rarely declare and open cursors or use any cursor-related Transact-SQL statements. ODBC automatically opens a cursor for every result set returned from an SQL statement. The characteristics of the cursors are controlled by statement attributes set with SQLSetStmtAttr before the SQL statement is executed. The ODBC API functions for processing result sets support the full range of cursor functionality, including fetching, scrolling, and positioned updates.

This is a comparison of how Transact-SQL scripts and ODBC applications work with cursors.

Action	Transact-SQL	ODBC
Define cursor behavior	Specify through DECLARE CURSOR parameters	Set cursor attributes by using SQLSetStmtAttr
Open a cursor	DECLARE CURSOR OPEN cursor_name	SQLExecDirect or SQLExecute
Fetch rows	FETCH	SQLFetch or SQLFetchScroll
Positioned update	WHERE CURRENT OF clause on UPDATE or DELETE	SQLSetPos
Close a cursor	CLOSE cursor_name DEALLOCATE	SQLCloseCursor

The server cursors implemented in SQL Server support the functionality of the ODBC cursor model. The SQL Server Native Client driver uses server cursors to support the cursor functionality of the ODBC API.

In This Section

• How Cursors Are Implemented

• Cursor Types

• Cursor Behaviors

• Cursor Properties

• Cursor Programming Details (ODBC)

• Scrolling and Fetching Rows

• Positioned Updates (ODBC)

See Also

Reference

CLOSE (Transact-SQL)

DEALLOCATE (Transact-SQL)

DECLARE CURSOR (Transact-SQL)

FETCH (Transact-SQL)

OPEN (Transact-SQL)

Concepts

SQL Server 2008 R2 Native Client (ODBC)

Cursors (Database Engine)