title: Finding difference between two tables in SQL
body: <p>I have two tables with exactly same schema. One is a week old and other is current. Let new record be new_data and the old be old_data. Both have a column called opportunity_id which is the primary key, sales stages(1,2,3,4..etc) and sales_values. Now in a week a sales stage may change for an opportunity or sales values of an opportunity may change. Even a new Opportunity_id may be added. I need all the data that has changed.</p>
  
  <p>I am trying INNER_JOIN but that only works when opportunity_ids match.I need newly added opportunities also.</p>
  
  <p>I am using MS Access, so please provide only sql solution.</p>
  
  <p>Thanks</p>