MDAC 2.5 SDK - OLE DB Providers
OSP Toolkit

OLEDBSimpleProvider::getEstimatedRows

Returns an estimate of the total number of rows in the data set. With an asynchronous provider, callers can use this method with OLEDBSimpleProvider::getRowCount to get an estimate of the percentage of data received.

HRESULT getEstimatedRows (
   LONG *   pcRows);

Parameter

pcRows

[out]
Estimated number of rows in the data set.

Return Codes

S_OK

The method succeeded.

E_FAIL

A provider-specific error occurred.

Comments

When an estimate of the number of rows cannot be provided, the provider should return a value of -1.

Synchronous providers should not block on a call to OLEDBSimpleProvider::getEstimatedRows. They should either return a value of -1 to indicate that they cannot provide an estimate, or they should provide the actual row count (the same as would be obtained through OLEDBSimpleProvider::getRowCount).

Providers should not return the final row count prior to issuing OLEDBSimpleProviderListener::transferComplete.