title: JPA does not return null value
body: <p>I have a Student table in JPA which contains fields id(primary key), studentName and the studentCode from that studentCode is nullable. So in my table, some rows contains the studentcode and some are not. When i tried to get the studentCode from the Student table, only the studentCode which are not null are being returned and the null value student code is not returning. I googled this. But I can't find the correct solution. </p>
  
  <p>I added the query such as </p>
  
  <pre><code>SELECT s.studentCode from Student s
  </code></pre>
  
  <p>and the studentCode of my table is <code>121,500,null,203,null,null</code> and so on. The query returns only the values of <code>121, 500, 203</code> and does not return the null value.</p>
  
  <p>The datatype are for id(int), studentName(varchar(25)), studentCode(varchar(10))</p>