title: Quickly add a copy of a column to a MySQL table
body: <p>I need a fast way duplicate a DATETIME column in a table and give it a new name.  </p>
  
  <p>I have a column named myDate in my table called myResults, I need a query to make a new column in the table called newDate which has the exact same data as the myDate column.   </p>
  
  <p>Is there a faster way to do this than by doing the obvious 2 step approach of make a new column, and then copying all the data (it's a large table and I'm looking for the fastest approach)?</p>
  
  <p>Obvious solution:  </p>
  
  <pre><code> ALTER TABLE `myResults` ADD `newDate` DATETIME;  
   UPDATE `myResults` SET `newDate` = `myDate`;
  </code></pre>