Mohini,
I also have B&S 2.3.1. The database file I received from SUN
does NOT have unique contractor names. I don't recommend
using name alone as your primary key in case they
test you system with a database file like mine.
I have chosen to use the recordId as my primary key and
I store this in my contractor value object. This is a
simple solution. Some people use a composite primary key
made of of name/location or name/location/specialties.
Good luck,
Karen Smrha