Using Dynamic Cursors with dbcursoropen

When you call the dbcursoropen function with a scrollopt parameter of CUR_DYNAMIC, the tables you specify in the SELECT statement of the stmt parameter no longer require unique indexes.

In SQL Server version 6.0, the cursor automatically opens with a scrollopt parameter of CUR_INSENSITIVE and a concuropt parameter of CUR_READONLY if the SELECT statement contains a table without a unique index.

In SQL Server 6.5, the cursor automatically opens with a scrollopt parameter of CUR_INSENSITIVE and a concuropt parameter of CUR_READONLY if the SELECT statement contains any of the following:

• ORDER BY and a table with no unique index
• UNION
• DISTINCT
• GROUP BY
• HAVING
• Aggregate function

SQL Server will copy the results into temporary work tables. Because all fetch operations are performed on the temporary tables, you cannot make changes to the cursor by using dbcursor.