INFO: Wizards Use CDataSource::OpenWithServiceComponents()

MORE INFORMATION

The OLE DB Service Components provide guaranteed functionality to OLE DB consumers above the minimum level required by OLE DB providers. The OLE DB 2.0 service components support:

• Scrolling, Find, and bookmark support against any minimum-level OLE DB provider.
• Updating against SQL providers.
• Resource pooling for pooling connections in a frequent connect/disconnect scenario.
• Automatic transaction enlistment in a Microsoft Transaction Server environment.

When using the MFC AppWizard with OLE DB support, a function C<ProjectName>Set::Open() is created. Within this function, a call to CDatasource::OpenWithServiceComponents() is made.

When using the ATL OLE DB Consumer Wizard, a function C<TableName>::OpenDataSource() is created. The following logic is used by the Consumer Wizard to determine whether CDataSource::Open() or CDataSource::OpenWithServiceComponents() is called from C<TableName>::OpenDataSource();.

1. The Wizard checks the provider to see if it supports IRowsetChange. If supported, the wizard generates code to call CDataSource::Open(). The OLE DB Service components are not required to obtain update functionality.
2. If the provider doesn't support IRowsetChange but does support SQL (the Wizard checks the DBPROP_SQLSUPPORT property of the DBPROPSET_DATASOURCEINFO property set), then the wizard generates code to call CDataSource::OpenWithServiceComponents(). The Service Components are required to obtain update functionality through SQL. The Microsoft Provider for Oracle is an example of such a provider.
3. If the provider doesn't support IRowsetChange and doesn't support SQL, then the wizard will not try to set any update properties. For 2 and 3, above, the wizard also generates a comment to explain what is happening.