title: How can I find a non duplicate value in a column, disregarding special characters?
body: <p>I have an attribute field of labels relevant to my work. I am looking for duplicates within this field; the issue is, the inputs are inconsistant.  For example:</p>
  
  <pre><code>Group  |  Label  |
  ---------------
  1      |  H7     |
  1      |  H-7    |
  2      |  C9     |
  2      |  C 9    |
  3      |  D5     |
  3      |  M 9    |
  </code></pre>
  
  <p>The result I am looking for is just:</p>
  
  <pre><code>3      |  D5     |
  3      |  M 9    |
  </code></pre>
  
  <p>as these are truly different from each other.  I am using the following query currently:</p>
  
  <pre><code>SELECT *
  FROM TABLE t3
  WHERE t3.group IN (
    SELECT t1.group
    FROM TABLE t1, TABLE t2
    WHERE t1.group = t2.group
    AND (t1.label &lt;&gt; t2.label) 
  </code></pre>
  
  <p>How can I get the query to disregard special characters?</p>