IDBSchemaRowsetImpl Class

Article
06/05/2017

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Provides implementation for schema rowsets.

Syntax

template <class SessionClass>  
class ATL_NO_VTABLE IDBSchemaRowsetImpl : public IDBSchemaRowset

Parameters

SessionClass
The class by which IDBSchemaRowsetImpl is inherited. Typically, this class will be the user's session class.

Members

Methods

CheckRestrictions	Checks the validity of restrictions against a schema rowset.
CreateSchemaRowset	Implements a COM object creator function for the object specified by the template parameter.
SetRestrictions	Specifies which restrictions you support on a particular schema rowset.

Interface Methods

GetRowset	Returns a schema rowset.
GetSchemas	Returns a list of schema rowsets accessible by IDBSchemaRowsetImpl::GetRowset.

Remarks

This class implements the IDBSchemaRowset interface and the templatized creator function CreateSchemaRowset.

OLE DB uses schema rowsets to return data about the data in a provider. Such data is often called "metadata." By default, a provider must always support DBSCHEMA_TABLES, DBSCHEMA_COLUMNS, and DBSCHEMA_PROVIDER_TYPES, as described in IDBSchemaRowset in the OLE DB Programmer's Reference. Schema rowsets are designated in a schema map. For information about the schema map entries, see SCHEMA_ENTRY.

The OLE DB Provider Wizard, in the ATL Object Wizard, automatically generates code for the schema rowsets in your project. (By default, the wizard supports the mandatory schema rowsets previously mentioned.) When you create a consumer using the ATL Object Wizard, the wizard uses schema rowsets to bind the correct data to a provider. If you do not implement your schema rowsets to provide the correct metadata, the wizard will not bind the correct data.

For information on how to support schema rowsets in your provider, see Supporting Schema Rowsets.

For more information about schema rowsets, see Schema Rowsets in the OLE DB Programmer's Reference.

Requirements

Header: atldb.h

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