title: Combining two tables using UNION ALL
body: <p>I have two tables with the same fields. I wish to combine these into one big table. Each table's primary key is a unique respondent id.</p>
  
  <p>When I combine the two tables with a UNION ALL, some data gets put into the wrong fields! Why is this? They are in the correct fields in the original tables. Is UNION ALL the correct operator?</p>