Supported OLE DB Interfaces

Data Source Object

Interface	Description
IConnectionPointContainer	When implemented on an object, makes the object connectable and expresses the existence of outgoing interfaces on the object. Through this interface a client can either locate a specific connection point for one IID or enumerate the connection points that exist. (This is a COM, not an OLE DB, interface. For more information, refer to the OLE DB Programmer's Reference.)
IDBAsynchStatus	Polls for status or cancels the asynchronous operation on the object being initialized, generated, or populated.
IDBCreateSession	Used by consumers to create a new session on a data source object.
IDBInitialize	Initializes a data source object or enumerator.
IDBProperties	Sets and gets the values of properties on the data source object or enumerator and gets all information about all properties supported by the provider.
IPersist	An interface that is implemented by object applications and used by container applications to get the CLSID associated with an object.
ISupportErrorInfo	Indicates whether a specific interface can return COM and OLE DB error objects.

Session Object

Interface	Description and Notes
IGetDataSource	Mandatory interface on the session for obtaining a data source object.
IOpenRowset	Enables consumers to open and work directly with individual tables or indexes in a data source. When using IOpenRowset::OpenRowset against an OLE DB provider written with the OSP Toolkit, you can issue OpenRowset only once for each OSP. The second call will fail with a status code of E_FAIL. If no data member is specified on IOpenRowset::OpenRowset—because no registration settings have been entered, or because no data source initialization property has been set—Msdaosp.dll returns the error DB_E_NOTABLE, which indicates that the table does not exist in the current data source.
ISessionProperties	Performs row updates, deletes, and inserts.
ISupportErrorInfo	Indicates whether a specific interface can return Automation and OLE DB error objects.

Rowset Object

Interface	Description
IAccessor	Provides methods for accessor management.
IColumnsInfo	Exposes information about columns of a rowset. (See Note below.)
IConnectionPointContainer	When implemented on an object, makes the object connectable and expresses the existence of outgoing interfaces on the object. Through this interface a client can either locate a specific connection point for one IID or enumerate the connection points that exist. (This is a COM, not an OLE DB, interface. For more information, refer to the OLE DB Programmer's Reference.)
IConvertType	Provides information about the availability of type conversions on a rowset.
IDBAsynchStatus	Polls for status or cancels the asynchronous operation on the object being initialized, generated, or populated.
IRowset	Provides methods for fetching rows sequentially, getting the data from those rows, and managing the rows.
IRowsetChange	Performs row updates, deletes, and inserts.
IRowsetFind	Allows consumers to find a row within the rowset matching a specified value.
IRowsetIdentity	Indicates that row instance identity is implemented on the rowset and enables testing for row identity.
IRowsetInfo	Provides information about a rowset.
IRowsetLocate	Fetches arbitrary rows of a rowset.
IRowsetScroll	Enables consumers to fetch rows at approximate positions in the rowset.
ISupportErrorInfo	Indicates whether a specific interface can return Automation and OLE DB error objects.

Note The OSP implementation of the IColumnsInfo::GetColumnInfo method initializes DBCOLUMNSINFO structures as follows.

For the bookmark column:

Column ID (DBID)—As described in the section "Bookmarks," in Chapter 4: Rowsets, of the OLE DB Programmer's Reference, where DBID.eKind is set to DBKIND_GUID_PROPID
wType—DBTYPE_I4 for a 32-bit OS, or DBTYPE_I8 for a 64-bit OS
uColumnSize—DBBKMARK, which is 4 for a 32-bit OS, or 8 for a 64-bit OS
bPrecision—10
bScale—~0 (all ones; no scale)
dwFlags—DBCOLUMNFLAGS_ISBOOKMARK | DBCOLUMNFLAGS_ISFIXEDLENGTH | DBCOLUMNFLAGS_MAYDEFER

For all other columns:

iOrdinal—A number starting from 1
DBID.eKind—DBKIND_PROPID
DBID.uName.ulPropid—A number equal to 100+iOrdinal
wType—DBTYPE_VARIANT
ulColumnSize—The size of a VARIANT (16)
bPrecision—~0 (all ones; no precision)
bScale—~0 (all ones; no scale)
dwFlags—DBCOLUMNFLAGS_ISFIXEDLENGTH | DBCOLUMNFLAGS_MAYDEFER | DBCOLUMNFLAGS_MAYBENULL | DBCOLUMNFLAGS_ISNULLABLE

If the OSP getRWStatus method reports the column is not OSPRW_READONLY, dwFlags is also marked DBCOLUMNFLAGS_WRITE.

If the column is a chapter column, wType is set to DBTYPE_HCHAPTER, dwFlags is marked DBCOLUMNFLAGS_ISCHAPTER, and ulColumnSize is set to the size of a pointer to IUnknown.

The column name is stored in **ppStringsBuffer.

Notification Interfaces for Rowset Object

Interface	Description
IDBAsynchNotify	The callback interface that a consumer must support to be notified of the progress of asynchronous operations such as initializing a data source object or opening or populating a rowset.
IRowsetNotify	The callback interface that a consumer must support to connect to local notifications provided by a rowset.