title: How to flatmap a nested Dataframe in Spark
body: <p>I have nested string like as shown below. I want to flat map them to produce unique rows in Spark</p>
  
  <p>My dataframe has</p>
  
  <pre><code>A,B,"x,y,z",D
  </code></pre>
  
  <p>I want to convert it to produce output like</p>
  
  <pre><code>A,B,x,D
  A,B,y,D
  A,B,z,D
  </code></pre>
  
  <p>How can I do that.</p>
  
  <p>Basically how can i do flat map and apply any function inside the Dataframe</p>
  
  <p>Thanks</p>