UPDATE and DELETE Statements

The following conditions must be satisfied for a remote table to be updated or deleted from a SQL Server distributed query:

• The provider must support bookmarks for the rowset opened through IOpenRowset on the table being updated or deleted.
• The provider must support the IRowsetLocate and IRowsetChange interfaces on the rowset opened through IOpenRowset for the table being updated or deleted.
• The IRowsetChange interface must support update (SetData) and delete (DeleteRows) methods.
• If the provider does not support ITransactionLocal, UPDATE/DELETE statements are allowed only if the Non-transacted option is set for that provider and if the statement is not in a user transaction.
• If the provider does not support ITransactionJoin, an UPDATE/DELETE statement is allowed only if it is not in a user transaction.

The following rowset properties are required on the rowset opened against the updated table: DBPROP_IRowsetLocate, DBPROP_IRowsetChange, and DBPROP_BOOKMARKS. The DBPROP_UPDATABILITY rowset property is set to DBPROPVAL_UP_CHANGE or DBPROPVAL_UP_DELETE depending on whether the operation performed is an UPDATE or a DELETE, respectively.

The following high-level steps against the provider for processing an UPDATE or DELETE operation are performed:

1. SQL Server opens the base table rowset through the IOpenRowset interface. SQL Server requires the above-mentioned properties on the rowset.
2. SQL Server determines the set of qualifying rows to be updated or deleted.
3. SQL Server uses the bookmarks to position on the qualifying rows through the IRowsetLocate interface.
4. Use IRowsetChange::SetData for UPDATE operations or IRowsetChange::DeleteRows for delete operations to perform the required changes on the qualifying rows.