title: SQL updating table with multiple conditions in the where statement ACCESS
body: <p>I'm trying to update multiple columns in a table. Here is an example of what I'm trying to do:</p>
  
  <p>Say I have this table:</p>
  
  <pre><code>User | Letter1 | Letter2 
   1   | 'A'     |  'X'
   2   | 'X'     |  'X'
   3   | 'R'     |  'G'
  </code></pre>
  
  <p>And i want to convert it to a table like this where all the X's are replaced by "_" (underscores).</p>
  
  <pre><code>User | Letter1 | Letter2 
   1   | 'A'     |  '_'
   2   | '_'     |  '_'
   3   | 'R'     |  'G'
  </code></pre>
  
  <p>I tried this:</p>
  
  <pre><code>Update table1 
  SET Letter1 = '_', Letter2 = '_'
  WHERE Letter1 = "X", Letter2 = "X"
  </code></pre>
  
  <p>However that doesn't work. Any help would be great.
  Thanks in advance</p>