title: MySQL, REPLACE INTO without deleting?
body: <p>I have this table structure:</p>
  
  <pre><code>ID RATE1 RATE2 RATE3
  </code></pre>
  
  <p>and its empty. Lets give a new rate:</p>
  
  <pre><code>REPLACE INTO rates (ID, RATE2) VALUES (99, 4);
  </code></pre>
  
  <p>the table will be:</p>
  
  <pre><code>99, 0, 4, 0
  </code></pre>
  
  <p>so far so good. Another rating takes place:</p>
  
  <pre><code>REPLACE INTO rates (ID, RATE3) VALUES (99, 2);
  </code></pre>
  
  <p>and this is where the error happens. I get</p>
  
  <pre><code>99, 0, 0, 2
  </code></pre>
  
  <p>instead of:</p>
  
  <pre><code>99, 0, 4, 2
  </code></pre>
  
  <p>I wanted to retain RATE2 too. Is there a workaround for this?</p>