title: RDS boto How to use database DEFAULT value
body: <p>I'm using AWS API gateway and boto3.client to execute SQL statements.</p>
  <p>I am tring to insert a row where I'd like the resulting query to be the database DEFAULT:</p>
  <pre><code>INSERT INTO mytable (name, ...) VALUES (DEFAULT, ...);
  </code></pre>
  <p>where the column has been defined as:</p>
  <pre><code>`name` varchar(191) NOT NULL DEFAULT 'db-default-name'
  </code></pre>
  <p>At run-time I sometimes have a string value for <code>name</code>, in which case I define the parameter like so:</p>
  <pre><code>{'name': name, {'value': {'stringValue': 'run-time-name'}}
  </code></pre>
  <p>But sometimes not and in those cases I'd like the DB default value to be inserted.</p>
  <p>I have tried this to set the parameter definition:</p>
  <pre><code>{'name': name, {'value': {'isNull': True}}
  </code></pre>
  <p>but then I get an error that the column cannot be NULL, which is correct, but doesn't help.</p>
  <p>If I specify None in my python code like so:</p>
  <pre><code>{'name': name, {'value': {'stringValue': None}}}
  </code></pre>
  <p>I get an error too about the None value, that it is not a string value ...</p>
  <p>Is there now way around this?</p>