Before you open the rowset, you must tell the provider that you want to use bookmarks. To do this, set the DBPROP_BOOKMARKS property to true in your property set. The provider retrieves bookmarks as column zero, so you must use the special macro BOOKMARK_ENTRY and the CBookmark class if you are using a static accessor. CBookmark is a template class where the argument is the length in bytes of the bookmark buffer. The length of the buffer required for a bookmark depends on the provider. If you are using the ODBC OLE DB provider, as shown in the following example, the buffer must be 4 bytes.

class CProducts  
{  
public:  
   CBookmark<4>   bookmark;  
  
   BEGIN_COLUMN_MAP(CProducts)  
      BOOKMARK_ENTRY(bookmark)  
   END_COLUMN_MAP()  
};  
  
CDBPropSet propset(DBPROPSET_ROWSET);  
propset.AddProperty(DBPROP_BOOKMARKS, true);  
  
CTable<CAccessor<CProducts> > product;  
product.Open(session, "Products", &propset);  

If you use CDynamicAccessor, the buffer is dynamically allocated at run time. In this case, you can use a specialized version of CBookmark for which you do not specify a buffer length. Use the function GetBookmark to retrieve the bookmark from the current record, as shown in this code sample:

CTable<CDynamicAccessor> product;  
CBookmark<>              bookmark;  
CDBPropSet propset(DBPROPSET_ROWSET);  
  
propset.AddProperty(DBPROP_BOOKMARKS, true);  
product.Open(session, "Products", &propset);  
product.MoveNext();  
product.GetBookmark(&bookmark);  

For information about supporting bookmarks in providers, see Provider Support for Bookmarks.

Using Accessors