title: Comparing two large SQL queries
body: <p>I am replacing an old untidy SQL query with a new version, because it was failing to include several rows it should have. </p>
  
  <p>The new query certainly includes these missing rows, but I want to be entirely sure that it also includes all of the rows from the original query.</p>
  
  <p>The two queries use entirely different tables. Each query is ~14000 rows.</p>
  
  <p>Is there a query I can write that checks whether QueryA contains any rows that QueryB does not have?</p>