title: Locally symmetric difference in sql
body: <p>I have  a  problem similar to <a href="https://stackoverflow.com/questions/68346/implement-symmetric-difference-in-sql-server">this StackOverflow question</a>, except that I need to exclude certain fields from the comparison but still include it in the result set.<br>
  I'm penning the problem as locally symmetric difference.</p>
  
  <p>For example Table A and B have columns X,Y,Z and I want to compare only Y,Z for differences but I still want the result set to include X.</p>