title: Conditional Rank
body: <p>So my concern is as follows:<br> 
  If I get a "match" in column 2 I need ranking else null Partition by Column 1 is this possible? So in below example rank is <code>1,2,3</code> since in Column 1 it has same column 1 (1003) for 1004 it has no match so I will be getting a null value</p>
  
  <p><strong>Expected output:</strong></p>
  
  <pre><code> Column 1 |  Column 2 | Rank
  -----------------------------
     1003   |  Match    |   1
     1003   |  Sorias   |   2
     1003   |  Pythn    |   3
     1004   |  Sorias   | null
     1004   |  Pythn    | null
     1004   |  Pythn    | null
  </code></pre>