title: MYSQL - Get unique minimum value
body: <p>In a table that has the columns: <code>'product_id', 'price',</code> ... (and others). I need to obtain the record with the lowest and unique price for a given product_id.<br>
  I tried different sentences without having the expected result. Finally I came across this sentence (for <code>product_id = 2</code>):</p>
  
  <pre><code>SELECT `price` , `product_id`
  FROM bids
  WHERE `product_id` = 2
  GROUP BY `price`
  HAVING COUNT( `price` ) = 1
  ORDER BY `price`
  LIMIT 1;
  </code></pre>
  
  <p>But it seems not to be an elegant solution having recourse to <code>LIMIT</code> and <code>ORDER</code>. How can I obtain the same record using the <code>MIN()</code> function or even something else?</p>