DAO ODBC via Jet Cursors

   

Data Access Objects (DAO) Open Database Connectivity (ODBC) via Jet uses recordsets rather than result sets to provide the several cursor types, as described in the following table.

Cursor type Recordset type Comments
Table Table Accesses the table directly. Inserts, updates, and deletes are made to the table directly.
Static Snapshot If your application does not need to see changes, a static cursor with a snapshot recordset may work. However, because a snapshot recordset stores a complete copy of all the records in a table, a snapshot may perform more slowly than a dynaset if the number of records is large. To determine whether a snapshot or dynaset is faster with your application's requirements, you can open the recordset as a dynaset and then open it again as a snapshot and measure the performance.
Keyset Dynaset If your application needs to see changed rows, and there is no concern about added or deleted rows, the keyset cursor with a dynaset recordset is a good choice.

You can control how the data source and the DAO ODBC via Jet cursors manage concurrency with the several locking options, as listed in the following table.

Locking type Constant
Detects value changes, causes error. dbSeeChanges
Prevents other processes from making changes. dbDenyWrite
Prevents other processes from reading the base table. dbDenyRead
Read only. Changes are not permitted. dbReadOnly

For More Information   For more information on the DAO ODBC via Jet library cursors, search online for "Advanced Data Access Solutions Using DAO and Jet" in MSDN Library Visual Studio 6.0. For more information on using locks to handle multiuser concurrency situations, see Managing Concurrency with Cursor Locks.