title: Oracle sql order by not working as expected?
body: <p>I have a table called 'ADDRESSES'.</p>
  
  <p>My query:</p>
  
  <pre><code>select MODIFIED_DATE, CITY from ADDRESSES order by MODIFIED_DATE desc, CITY asc;
  </code></pre>
  
  <p>By running the above query I get:</p>
  
  <pre><code>MODIFIED_DATE   CITY
  =============   ==============
  13-JAN-16       CHICAGO
  13-JAN-16       CHICAGO
  13-JAN-16       CHICAGO
  13-JAN-16       KANSAS CITY
  13-JAN-16       KANSAS CITY
  13-JAN-16       KANSAS CITY
  13-JAN-16       KANSAS CITY
  13-JAN-16       KANSAS CITY
  13-JAN-16       CHICAGO
  13-JAN-16       CHICAGO
  13-JAN-16       DENVER
  13-JAN-16       DENVER
  </code></pre>
  
  <p>But I expect:</p>
  
  <pre><code>MODIFIED_DATE   CITY
  =============   ==============
  13-JAN-16       CHICAGO
  13-JAN-16       CHICAGO
  13-JAN-16       CHICAGO
  13-JAN-16       CHICAGO
  13-JAN-16       CHICAGO
  13-JAN-16       DENVER
  13-JAN-16       DENVER
  13-JAN-16       KANSAS CITY
  13-JAN-16       KANSAS CITY
  13-JAN-16       KANSAS CITY
  13-JAN-16       KANSAS CITY
  13-JAN-16       KANSAS CITY
  </code></pre>
  
  <p>The data type of MODIFIED_DATE is DATE and the data type of CITY is VARCHAR2.</p>
  
  <p>Why is this happening?</p>