title: How to sort columns in MYSQL
body: <p>I have three fields in each row and I want to concatenate them, sorted ascending:</p>
  
  <pre><code>select * concat(field1, field2, field3) AS result
  from tbl 
  </code></pre>
  
  <p>My data is:</p>
  
  <pre><code>field1, field2, field3
     7       2       9
     4       7       8
     6       3       2 
  </code></pre>
  
  <p>The expected result is:</p>
  
  <pre><code>field1, field2, field3   result
    7       2       9       279
    4       7       8       478
    6       3       2       236
  </code></pre>
  
  <p>How can I do this?</p>