title: negative selection SQL Query
body: <p>I have been tasked with returning a negative selection from our sql database. I'll define the criteria as best i can. Thus far I haven't crafted a query that has worked. </p>
  
  <h2>Business Table</h2>
  
  <p>[Bus Name] [Bus ID]</p>
  
  <h2>Activity Table</h2>
  
  <p>[Activity ID] [Bus ID]</p>
  
  <h2>Activity Extension Table</h2>
  
  <p>[Ext ID] [Activity ID] [Bus ID]</p>
  
  <p>I need the Business names for all businesses that do not have a record with that businesses id # in the associated tables. Simply put, all businesses without activities. The Business ID can be present in one or both of the associated tables. </p>
  
  <p>This has caused me trouble for a few hours while trying to craft queries with joins and not exists or not in statements. No success. </p>
  
  <p>Any ideas?</p>