title: How to filter rows having array of struct?
body: <p>I have a dataFrame with array of struct so I just want to filter columns or we can say select column in array of struct from the array of struct but is it possible as I am iterating through row .
  Schema</p>
  
  <pre><code> root 
       |-- day: long (nullable = true)
       |-- table_row: array (nullable = true)
       |    |-- element: struct (containsNull = true)
       |    |-- DATE: string (nullable = true)
       |    |-- ADMISSION_NUM: string (nullable = true)
       |    |-- SOURCE_CODE: string (nullable = true)
  </code></pre>
  
  <p>What I am doing is that I am iterating through Rows Can we select the array columns row wise . I only want to know how this is possible</p>
  
  <pre><code>def keepColumnInarray(columns: Set[String], row: Row): Row = {
        //Some 
      }
  </code></pre>
  
  <p>Example If I want to keep column "Data" Then keepColumnInarray will only select this</p>
  
  <p>Output Schema</p>
  
  <pre><code> root 
       |-- day: long (nullable = true)
       |-- table_row: array (nullable = true)
       |    |-- element: struct (containsNull = true)
       |    |-- DATE: string (nullable = true)
  
  
  </code></pre>