title: Can not set int field to null value
body: <p>I have this <code>int</code> column:</p>
  
  <pre><code>@Column(length = 4)
  private int contract_owner_id;
  </code></pre>
  
  <p>I don't need to set always value for every table row. I get this exception when I make select query:</p>
  
  <pre><code>Can not set int field org.entity.contracts.contract_owner_id to null value
  </code></pre>
  
  <p>Is there some way to set numb setups when there is no data into the table column?</p>