title: Merge two datatable in to one datatable and remove duplicate as per single column
body: <p>I have two datatable, say T1 and T2. Following are the columns in both table:</p>
  
  <pre><code>1) Filename,
  2) Size,
  3) PATH,
  4) rank,
  5) DocTitle,
  6) HitCount
  </code></pre>
  
  <p>Now, I need to merge table T1 and T2 but entries should not get duplicated as per "Filename" column.</p>
  
  <p>I cant user <code>T1.Merge(T2)</code> to do my work. Do anyone have suggestion on the same. Thanks.</p>