Using the ODBC Cursor Library

To use the ODBC cursor library, an application:

1. Calls SQLSetConnectAttr with an Attribute of SQL_ATTR_ODBC_CURSORS to specify how the cursor library should be used with a particular connection. The cursor library can be always used (SQL_CUR_USE_ODBC), used only if driver does not support scrollable cursors (SQL_CUR_USE_IF_NEEDED), or never used (SQL_CUR_USE_DRIVER).
   
   
2. Calls SQLConnect, SQLDriverConnect, or SQLBrowseConnect to connect to the data source.
   
   
3. Calls SQLSetStmtAttr to specify the cursor type (SQL_ATTR_CURSOR_TYPE), concurrency (SQL_ATTR_CONCURRENCY), and rowset size (SQL_ATTR_ROW_ARRAY_SIZE). The cursor library supports forward-only and static cursors. Forward-only cursors must be read-only, while static cursors may be read-only or use optimistic concurrency control comparing values.
   
   
4. Allocates one or more rowset buffers and calls SQLBindCol one or more times to bind these buffers to result set columns.
   
   
5. Generates a result set by executing a SELECT statement or a procedure, or by calling a catalog function. If the application will execute positioned update statements, it should execute a SELECT FOR UPDATE statement to generate the result set.
   
   
6. Calls SQLFetch or SQLFetchScroll one or more times to scroll through the result set.

The application can change data values in the rowset buffers. To refresh the rowset buffers with data from the cursor library’s cache, an application calls SQLFetchScroll with the FetchOrientation argument set to SQL_FETCH_RELATIVE and the FetchOffset argument set to 0.

To retrieve data from an unbound column, the application calls SQLSetPos to position the cursor on the desired row. It then calls SQLGetData to retrieve the data.

To determine the number of rows that have been retrieved from the data source, the application calls SQLRowCount.