update left outer join recordset

From: terry (terry_at_discussions.microsoft.com)
Date: 07/20/04 

Date: Tue, 20 Jul 2004 09:03:04 -0700

I user a sql to get a ado recordset from to tables
SQL: select * from table1 left outer join table2 on table1.pk = table2.pk

I modify some field that own by table2 in this recordset, but how can I update thoise field to table2? is there any way to kown which record is new for table2?