title: Why does tWriteJSONField create an array for null values?
body: <p>I have joined Countries to Locations in the HR Sample database in OracleXE.</p>
  
  <p>I am then using a tMap to generate a nested JSON document.</p>
  
  <p><a href="https://i.stack.imgur.com/1rj6e.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1rj6e.png" alt="enter image description here"></a></p>
  
  <p>it works, but for some reason null values in the Location are coming through as arrays in the final output in the console (have also tried MongoDB).</p>
  
  <p><a href="https://i.stack.imgur.com/dcPsX.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dcPsX.png" alt="enter image description here"></a></p>