DFX_Double

Transfers double float data between the field data members of a CDaoRecordset object and the columns of a record on the data source.

void AFXAPI DFX_Double(
   CDaoFieldExchange* pFX,
   LPCTSTR szName,
   double& value,
   DWORD dwBindOptions = AFX_DAO_ENABLE_FIELD_CACHE 
);

Parameters

pFX
A pointer to an object of class CDaoFieldExchange. This object contains information to define the context for each call of the function.
szName
The name of a data column.
value
The value stored in the indicated data member — the value to be transferred. For a transfer from recordset to data source, the value, of type double, is taken from the specified data member. For a transfer from data source to recordset, the value is stored in the specified data member.
dwBindOptions
An option that lets you take advantage of MFC's double buffering mechanism for detecting recordset fields that have changed. The default, AFX_DAO_ENABLE_FIELD_CACHE, uses double buffering. The other possible value is AFX_DAO_DISABLE_FIELD_CACHE. If you specify this value, MFC does no checking on this field. You must call SetFieldDirty and SetFieldNull yourself.

Observação

You can control whether data is double buffered by default by setting CDaoRecordset::m_bCheckCacheForDirtyFields.

Data is mapped between type DAO_R8 in DAO and type double float in the recordset.

Header: afxdao.h