Dear, I am facing a problem in sage 300, I already have two companies in sage 300, but when I open a new company one old one company disconnected from data base, now my old company doesn't show any thing, kindly advise me

  ANY BODY HERE TO HELP OUT MY PROBLEM, I AM WORRY ABOUT MY DATA, MY DUMP FILE OVER WRITE ON 2ND COMPANY, SO NOW I HAVE ALL BACKUP IN SQL, PLZZ HELP ME, HOW I RETRIEVE MY DATA USING SQL BACKUP, .