>>>In the database the column is smallint and defined as short in the class definition.
>>
>>So why is the Convert.ToInt16 needed?
>
>I think it's not needed, I'll remove it. In my original code it was needed as the result was anonymous type.
>
>So, the code now is reduced to
>
>

>var lastLocSuffix = _salespointAdapter.GetAll().Max(sp=>sp.LocSuffix);
>            Int16 newSuffix = 1;
>            if (lastLocSuffix != null)
>            {
>                newSuffix = lastLocSuffix++;                
>            }
>
>            salespoint.LocSuffix = newSuffix;

The ++ operator after the variable is done after the assignment (that is, the assignment happens first, then lastLocSuffix is incremented). So if GetAll().Max() returned 1, newSuffix would be assigned a 1 (not a 2).

You would want:

newSuffix = ++lastLocSuffix;

I'd actually end up trying to write the above as:

var lastLocSuffix = _salespointAdapter.GetAll().Max(sp=>sp.LocSuffix) ?? (short)0;
salespoint.LocSuffix = ++lastLocSuffix;

actually, this is probably easier to understand and avoids the assignment to lastLocSuffix which probably isn't needed anyway:

var lastLocSuffix = _salespointAdapter.GetAll().Max(sp=>sp.LocSuffix) ?? (short)0;
salespoint.LocSuffix = lastLocSuffix + 1;