title: SQL UNION without using the individual column names
body: <p>I want to take the union of two tables. They both have unequal number of columns and some of them are in common and some are not.</p>
  
  <p>How would i take its union them without using the individual column names (inserting dummy columns in between). </p>
  
  <p>I have to query and take the union of couple of tables and would be testing on different databases, which would have different column names for the same table. 
  Hence, i could not use the common way of addressing the individual column names and inserting dummy columns to get the union.</p>
  
  <p>Thanks,
  gokul.</p>