set_primary_key issue

Hi:

I am new to the ruby and rails. What I am tried to do is to create a scaffold based on an existing table in a MS SQL Server database.

Before I used the set_primary_key method, edit and show does not work in the generated code. Rails displayed the list of the records ok, but can not determine the id for each record. Create a new record does work properly, however.

After I used the set_primary_key method to set the right primary key (Uesr_ID), rails can now determine the id for each records when list of the records is displayed. But update does not work properly. looking at the development log, the update sql statement generated included all fields except the primary key field under Set cause. Creating a new record, also generated similar sql insert statement. The primary key is not included. BTW, for new record function to work, I have to modify the controller's new method to initialise the id field, otherwise I will receive "undefined method `UserID_before_type_cast' " exception.

Look back to the development log, before the set_primary_key method is used, generated insert statement for the new record does include all fields.

To me, it seems that the activerecord has excluded the primary key field when generating update and insert statement when the set_primary_key method is used.

Can anyone point me to the right direction to resolve this issue?

Thanks.