title: Spark scala : select column name from other dataframe
body: <p>There are two json and first json has more column and always it is super set.</p>
  
  <pre><code>val df1 = spark.read.json(sqoopJson)
  val df2 = spark.read.json(kafkaJson)
  </code></pre>
  
  <p><strong>Except Operation :</strong></p>
  
  <p>I like to apply except operation on both df1 and df2, But df1 has 10 column and df2 has only 8 columns.
  In case manually if i drop 2 column from df1 then except will work. But I have 50+ tables/json  and need to do EXCEPT for all 50 set of tables/json.</p>
  
  <p><strong>Question :</strong></p>
  
  <p>How to select only columns available in DF2 ( 8) columns from DF1 and create new df3? So df3 will have data from df1 with limited column and it will match with df2 columns.</p>