Cursor Behaviors

ODBC supports the SQL-92/ISO options for specifying the behavior of cursors by specifying their scrollability and sensitivity. These behaviors are specified by setting the SQL_ATTR_CURSOR_SCROLLABLE and SQL_ATTR_CURSOR_SENSITIVITY options on a call to SQLSetStmtAttr. The Microsoft® SQL Server™ ODBC driver implements these options by requesting server cursors with the following characteristics:

Cursor behavior settings	Server cursor characteristics requested
SQL_SCROLLABLE and SQL_SENSITIVE	Keyset-driven cursor and version-based optimistic concurrency
SQL_SCROLLABLE and SQL_INSENSITIVE	Static cursor and read-only concurrency
SQL_SCROLLABLE and SQL_UNSPECIFIED	Static cursor and read-only concurrency
SQL_NONSCROLLABLE and SQL_SENSITIVE	Forward-only cursor and version-based optimistic concurrency
SQL_NONSCROLLABLE and SQL_INSENSITIVE	Default result set (forward-only, read-only)
SQL_NONSCROLLABLE and SQL_UNSPECIFIED	Default result set (forward-only, read-only)

Version-based optimistic concurrency requires a timestamp column in the underlying table. If version-based optimistic concurrency control is requested on a table that does not have a timestamp column, the server uses values-based optimistic concurrency.

Scrollability

When SQL_ATTR_CURSOR_SCROLLABLE is set to SQL_SCROLLABLE, the cursor supports all of the different values for the FetchOrientation parameter of SQLFetchScroll. When SQL_ATTR_CURSOR_SCROLLABLE is set to SQL_NONSCROLLABLE, the cursor only supports a FetchOrientation value of SQL_FETCH_NEXT.

Sensitivity

When SQL_ATTR_CURSOR_SENSITIVITY is set to SQL_SENSITIVE, the cursor reflects data modifications made by the current user or committed by other users. When SQL_ATTR_CURSOR_SENSITIVITY is set to SQL_INSENSITIVE, the cursor does not reflect data modifications.