Contains the number of field data members in the recordset class and the number of columns selected by the recordset from the data source.
The constructor for the recordset class must initialize m_nFields with the correct number of statically bound fields. ClassWizard writes this initialization for you when you use it to declare your recordset class. You can also write it manually.
The framework uses this number to manage interaction between the field data members and the corresponding columns of the current record on the data source.
This number must correspond to the number of output columns registered in DoFieldExchange after a call to SetFieldType with the parameter CDaoFieldExchange::outputColumn.
You can bind columns dynamically by way of CDaoRecordset::GetFieldValue and CDaoRecordset::SetFieldValue. If you do so, you do not need to increment the count in m_nFields to reflect the number of DFX function calls in your DoFieldExchange member function.