>>>To repeat : The Update command is constructed based on the Select command
>>>
>>>You're selecting everything so it's updating everything.
>>>
>>My point is - why does it even update PK column and why does it construct such ugly where clause?
>
>It updates the PK because it is in your Select command.
>
>>Assuming I will only change the UpdateCommand.CommandText manually, will it still work?
>
>Yes, but what's the point.
>You should refine the Select command to only retrieve the fields that you want included in the Update command.
>
>Did you actually read the documentation?

I did check it. Is there any other approach I can use? I can not change the select command, the table has lots of columns and many of them I need to make decisions. However, only a handful (about 12) I am going to really update.