title: SQL Server : SUM () for only numeric values, ignoring Varchar values
body: <p>I need some help as I am learning SQL so I am at a beginner level. I am using SQL Server 2008 R2.   </p>
  
  <p>My question is: I want to (add) sum up a column that have mix values of <code>varchar</code> and <code>decimal</code>. I want to ignore the <code>varchar</code> values and sum only <code>decimal</code>. My column is like this:</p>
  
  <pre><code>Column1  
  -------
  0.1  
  Z  
  0.4  
  2.1  
  2.1  
  Z
  </code></pre>
  
  <p>And I need the sum that is in this case it should be: <code>4.7</code></p>
  
  <p>I tried using <code>CASE</code> but I failed to solve it  </p>
  
  <pre><code>SELECT 
      SUM(CASE 
             WHEN ISNUMERIC(Column1) = 1 
                THEN .(if true how i add them?). 
                ELSE .(and if false how i ignore them?). 
           END) AS Total 
  FROM
      TABLE_Name
  </code></pre>
  
  <p>I am not good in explaning things, but I hope you can understand me what I am trying to do.  </p>
  
  <p>If this question is already answered please give me directions to that question and my appologise for that.. Many thanks in advance :)</p>