title: SQL - Merge records by ID field
body: <p>I have a select statement where I get</p>
  
  <pre><code>ProductID  Gender Color Type     AgeRange
  344842     Boys   NULL  NULL     NULL       
  344842     NULL   Black NULL     NULL
  344842     NULL   NULL  Leggings NULL   
  344842     NULL   NULL  NULL     2 to 4 Years
  </code></pre>
  
  <p>I wish to get merged row like this</p>
  
  <pre><code>ProductID  Gender Color Type     AgeRange
  344842     Boys   Black Leggings 2 to 4 Years
  </code></pre>