Hi,

Thanks for your reply.  My select statemnet is very simple for testing.

                using (SqlDataAdapter adapter = new SqlDataAdapter("select id, f1 from table_1 where id = '1'", sqlConnection))   //Make sure that your xxx table must have a primary key
                    {
                       SqlCommandBuilder sub = new SqlCommandBuilder(adapter);
                       SqlCommand cmd = sub.GetUpdateCommand();
                    }

id field is the PK of this table. It show the same error. 

My SQL environment :

Server 1: Microsoft SQL Server 2008 R2 (RTM) - 10.50.1600.1 (X64)   (Build 7601: Service Pack 1)

This is the primary server and built an synonyms table to Server 2

Server 2: Microsoft SQL Server  2000 - 8.00.2040 (Intel X86)   (Build 3790: Service Pack 2)

Thanks

Wilson