title: delete duplicate rows from my table
body: <p>i need to delete all duplicate rows in my table - but leave only one row</p>
  
  <pre><code>MyTbl
  ====
  Code     |  ID  |  Place  |  Qty  |  User
  ========================================
  1        |  22 |   44     |  34   |  333
  2        |  22 |   44     |  34   |  333
  3        |  22 |   55     |  34   |  333
  4        |  22 |   44     |  34   |  666
  5        |  33 |   77     |  12   |  999
  6        | 44  |   11     |  87   |  333
  7        | 33  |   77     |  12   |  999
  </code></pre>
  
  <p>i need to see this:</p>
  
  <pre><code>Code    | ID  |  Place  |  Qty  |  User
  =======================================
  1       | 22 |   44     |  34   |  333
  3       | 22 |   55     |  34   |  333
  4       | 22 |   44     |  34   |  666
  5       | 33 |   77     |  12   |  999
  6       | 44 |   11     |  87   |  333
  </code></pre>