title: pg-promise: Transactions: Handling missing properties
body: <p>This is the query I pass into a batch transaction:</p>
  
  <pre><code>INSERT INTO table VALUES(${id}, ${name}, ${crtd});
  </code></pre>
  
  <p>The input array may or may not contain one of the keys, say <code>${crtd}</code>.
  This throws <code>Error: property 'crtd' does not exist</code> and the entire batch fails.</p>
  
  <p>I still want this row to be inserted, containing only <code>{id}</code> and <code>{name}</code>. The <code>${crtd}</code> is a nullable column too.</p>
  
  <p>In the below, 'l' is the input json missing the key ${crtd}.</p>
  
  <pre><code>                           db.tx(t=&gt;t.batch(valuesArray.map(l=&gt;t.none(query, l))))                         So, the only way to do this is additional logic that checks for missing keys and adds them?
  </code></pre>
  
  <p>How to handle this?</p>