title: Update datatable field based on the value exist in another datatable in Asp.net c#
body: <p>Hi I have two datatable</p>
  <h1>table</h1>
  <pre>
  id  isfav
  1   0
  2   0
  3   0
  4   0
  5   0
  </pre>
  <h1>favtable</h1>
  <pre>
  id 
  2
  3
  </pre>
  <p>So I want to Update the <code>table1</code> field <code>isFav</code> to 1 if the ids exist in <code>FavTable</code>.</p>
  <p>Can anybody help me on this</p>