title: How to set up custom fields in Superset?
body: <p>Our database has a field with JSON data that we'd like to use in reports. E.g.</p>
  <pre><code>{
    owner_type: &quot;USER&quot;,
    updated_at: 1641996749092389600,
    version_no: 1,
    entity_type: &quot;INDIVIDUAL&quot;,
    country:&quot;ES&quot;,
  } 
  </code></pre>
  <p>How can one create dynamic fields in Superset, e.g. to expose <code>owner_type</code> as its own field?</p>
  <p>I'm coming from tools like Snowflake and Zoho Analytics where you could build Views, Dynamic Tables and Formula Fields based on aggregated raw data.</p>