ADO Recordset Object Remarks

Use Recordset objects to manipulate data from a provider. In ADO, data is almost entirely manipulated using Recordset objects. All Recordset objects are constructed using records (rows) and fields (columns). Depending on the functionality supported by the provider, some Recordset methods or properties may not be available.

Recordset objects can also be run remotely. For example, in a Web-based application, you can open a Recordset on the client, using the progID "ADOR." The Remote Data Service provides a mechanism for local data caching and local cursor movement in remote recordset data. A client-side recordset can be used in the same way as a server-side recordset, and supports almost all of the Recordset object's normal methods and properties. Recordset methods and properties that are not supported on a client-side recordset, or that behave differently, are noted in the topics for those properties and methods.


Cursor	Description
Dynamic	Allows you to view additions, changes and deletions by other users, and allows all types of movement through the recordset that don’t rely on bookmarks; allows bookmarks if the provider supports them.
Keyset	Behaves like a dynamic cursor, except that it prevents you from seeing records that other users add, and prevents access to records that other users delete. Data change by other users will still be visible. It always supports bookmarks and therefore allows all types of movement through the recordset.
Static	Provides a static copy of a set of records for you to use to find data or generate reports. Always allows bookmarks and therefore allows all types of movement through the recordset. Additions, changes, or deletions by other users will not be visible. This is the only type of cursor allowed when you open a client-side (ADOR) Recordset object.
Forward-only	Behaves identically to a dynamic cursor except that it allows you to scroll only forward through records. This improves performance in situations where you need to make only a single pass through a recordset.

Set the ADO Recordset Object CursorType Property prior to opening the recordset to choose the cursor type, or pass a CursorType argument with the ADO Recordset Object Open Method. Some providers don't support all cursor types. Check the documentation for the provider. If you don't specify a cursor type, ADO opens a forward-only cursor by default.

When used with some providers (such as the Microsoft ODBC Provider for OLE DB in conjunction with Microsoft SQL Server), you can create Recordset objects independently of a previously defined ADO Connection Object by passing a connection string with the Open method. ADO still creates a Connection object, but it doesn't assign that object to an object variable. However, if you are opening multiple Recordset objects over the same connection, you should explicitly create and open a Connection object; this assigns the Connection object to an object variable. If you do not use this object variable when opening your Recordset objects, ADO creates a new Connection object for each new recordset, even if you pass the same connection string.

When you open a recordset, the current record is positioned to the first record (if any) and the ADO Recordset Object BOF, EOF Properties are set to False. If there are no records, the BOF and EOF property settings are True.

Use the ADO Recordset Object MoveFirst, MoveLast, MoveNext, MovePrevious Methods, as well as the ADO Recordset Object Move Method, and the AbsolutePosition, AbsolutePage, and ADO Recordset Object Filter Property properties to reposition the current record, assuming the provider supports the relevant functionality. Forward-only Recordset objects support only the MoveNext method. When you use the Move methods to visit each record (or enumerate the recordset), you can use the BOF and EOF properties to see if you've moved beyond the beginning or end of the recordset.

Recordset objects may support two types of updating: immediate and batched. In immediate updating, all changes to data are written immediately to the underlying data source once you call the ADO Recordset Object Update Method. You can also pass arrays of values as parameters with the ADO Recordset Object AddNew Method and Update methods and simultaneously update several fields in a record.

If a provider supports batch updating, you can have the provider cache changes to more than one record and then transmit them in a single call to the database with the ADO Recordset Object UpdateBatch Method. This applies to changes made with the AddNew, Update, and ADO Recordset Object Delete Method methods. After you call the UpdateBatch method, you can use the ADO Recordset Object Status Property to check for any data conflicts in order to resolve them. Batch updating is not currently supported on UNIX.