The classes and interfaces for the OLE DB Provider Templates can be grouped into the following categories. The reference material also includes information about the macros for OLE DB Provider Templates.
The classes use the following naming convention: a class named with the pattern IWidgetImpl would provide an implementation of the interface IWidget.
Session Classes
Creates a new command from the session object and returns the requested interface on the newly created command. Optional interface on session objects.
Implements session properties by calling a static function defined by the property set map. The property set map should be specified in your session class. Mandatory interface on sessions.
Obtains an interface pointer to the data source object. Mandatory interface on the session.
Opens and returns a rowset that includes all rows from a single base table or index. Mandatory interface for a session object.
Rowset Classes
Provides a standard OLE DB rowset implementation without requiring multiple inheritance of many implementation interfaces. The only method for which you must provide implementation is Execute.
Provides an implementation of the IRowset interface, which is the base rowset interface.
Provides a default implementation for the row handle, which is used in the IRowsetImpl class. A row handle is logically a unique tag for a result row. IRowsetImpl creates a new CSimpleRow for every row requested in IRowsetImpl::GetNextRows.
OLE DB requires providers to implement an HACCESSOR, which is a tag to an array of DBBINDING structures. Provides HACCESSORs that are addresses of the BindType structures. Mandatory on rowsets and commands.
Implements the rowset properties by using the property set map defined in your command class. Mandatory interface on rowsets.
Delegates to a static function defined by the provider column map. Mandatory interface on rowsets and commands.
Gives information on the availability of type conversions on a command or on a rowset. Mandatory on commands, rowsets, and index rowsets. Implements the IConvertType interface by delegating to the conversion object supplied by OLE DB.
Implements the IDBSchemaRowset interface and the templatized creator function CreateSchemaRowset.
Command Classes
Sets, stores, and returns the command text. Mandatory on commands.
Provides an implementation of the ICommand interface. This interface is not visible, but is handled by ICommandTextImpl. A mandatory interface on the command object.
This implementation of the ICommandProperties interface is provided by a static function defined by the BEGIN_PROPSET_MAP macro. Mandatory on commands.
Other command classes are IColumnsInfoImpl and IAccessorImpl, described in the Rowset Classes section above.
Data Source Classes
Creates and deletes the connection with the consumer. Mandatory interface on data source objects and optional interface on enumerators.
IDBProperties is a mandatory interface for data source objects and an optional interface for enumerators. However, if an enumerator exposes IDBInitialize, it must expose IDBProperties (properties on the data source).
Creates a new session from the data source object and returns the requested interface on the newly created session. Mandatory interface on data source objects.
Other Classes
Implements properties for a variety of OLE DB property interfaces (for example, IDBProperties, ISessionProperties, and IRowsetInfo).
See Also
List of OLE DB Consumer Templates, Home Page for OLE DB Template Classes