Page 274 - DCAP408_WEB_PROGRAMMING

Web Programming

Notes Set the CursorType property prior to opening the Recordset to choose the cursor type, or pass a
CursorType argument with the 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.
If the CursorLocation property is set to adUseClient to open a Recordset, the UnderlyingValue
property on Field objects is not available in the returned Recordset object. 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 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.

Notes 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.

12.1.1 CursorType Property

Indicates the type of cursor used in a Recordset object.

Settings and Return Values

Sets or returns a CursorTypeEnum value. The default value is adOpenForwardOnly.

Remarks

Use the CursorType property to specify the type of cursor that should be used when opening the
Recordset object.
Only a setting of adOpenStatic is supported if the CursorLocation property is set to adUseClient.
If an unsupported value is set, then no error will result; the closest supported CursorType will
be used instead.
If a provider does not support the requested cursor type, it may return another cursor type. The
CursorType property will change to match the actual cursor type in use when the Recordset
object is open. To verify specific functionality of the returned cursor, use the Supports method.
After you close the Recordset, the CursorType property reverts to its original setting.
The following chart shows the provider functionality (identified by Supports method constants)
required for each cursor type.

For a Recordset of this CursorType The Supports method must return True for all of these constants
adOpenForwardOnly None
AdOpenKeyset adBookmark, adHoldRecords, adMovePrevious, adResync
adOpenDynamic AdMovePrevious
AdOpenStatic adBookmark, adHoldRecords, adMovePrevious, adResync

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