title: Get unique entries for Item and Date Manufactured with minimum retailer id
body: <p>I have a table with these three attributes, say:</p>
  
  <pre><code>ItemID varchar(20),
  RetailerID int,
  ItemMfd_Date DATE
  </code></pre>
  
  <p>Now I want all those records such that if there are multiple retailers for a given <strong><code>Item</code> + <code>ItemMfd_Date</code></strong> we need to pick the row that is with minimum <code>RetailerID</code>. </p>
  
  <p>Suppose we have two attribute additional, and we want one more attribute as result but condition is those records must have attr2 = 1</p>