Why can't my query update a linked table? I have a query in MS Access that has a linked (ODBC) SQL Server table as it's source. To get the results I need the query uses three separate fields for criteria. The query returns the correct data set, however when any data is changed / updated in the query, a write conflict message occurs. The exact message is: "This record has been changed by another user since you started editing it. If you save the record, you will overwrite the changes the other user made." There are no other users, and the SQL tables have been created with at least one primary key.

If two of the criteria are removed the query then becomes updateable. Is this a limitation (only one criteria field) of a query using a linked SQL Server table?

Any help would be greatly appreciated.