CBulkRowset Class

Artykuł
06/05/2017

The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.

The latest version of this topic can be found at CBulkRowset Class.

Fetches and manipulates rows to work on data in bulk by retrieving multiple row handles with a single call.

Syntax

template <class TAccessor>  
class CBulkRowset : public CRowset<TAccessor>

Parameters

TAccessor
An accessor class.

Members

Methods

AddRefRows	Increments the reference count.
CBulkRowset	Constructor.
MoveFirst	Retrieves the first row of data, performing a new bulk fetch if necessary.
MoveLast	Moves to the last row.
MoveNext	Retrieves the next row of data.
MovePrev	Moves to the previous row.
MoveToBookmark	Fetches the row marked by a bookmark or the row at a specified offset from that bookmark.
MoveToRatio	Fetches rows starting from a fractional position in the rowset.
ReleaseRows	Sets the current row (m_nCurrentRow) to zero and releases all rows.
SetRows	Sets the number of row handles to be retrieved by one call.

Example

The following example demonstrates use of the CBulkRowset class.

class CCustomerData
{
public:
   char m_szField1[50];

   BEGIN_COLUMN_MAP(CCustomerData)
     COLUMN_ENTRY(1, m_szField1)
   END_COLUMN_MAP()
};

void DoCBulkRowsetTest()
{
   CoInitialize(NULL);

   CCommand<CAccessor<CCustomerData>, CBulkRowset > cmd;
   CDataSource ds;

   // Open up data link dialogs to create a data source
   ds.Open();

   CSession session;
   session.Open(ds);
   // Could call SetRows() here if you want to fetch 
   // more than 10 HROWs at a time.
   cmd.Open(session, L"Select * from customer");
   cmd.MoveFirst();
   // Note that the CBulkRowset by default fetched 10 HROWs at a time 
   // so that the MoveNext call will not have to make the GetNextRows 
   // call to get the second HROW because it has already been fetched 
   //by the MoveFirst() call above.
   cmd.MoveNext();

   cmd.Close();
   session.Close();
   ds.Close();
}

Requirements

Header: atldbcli.h

Udostępnij za pośrednictwem