title: How to use PostgreSQL JSONB_SET() to create new deep object element
body: <p>I must be missing something... seems <code>JSONB_SET()</code> is not working as <a href="https://www.postgresql.org/docs/9.6/static/functions-json.html" rel="noreferrer">advertised</a>?</p>
  
  <pre><code>SELECT JSONB_SET(
      '{"k1": {"value": "v1"}}',
      '{k2,value}',
      '"v2"',
      TRUE
  );
  </code></pre>
  
  <p>Results in:</p>
  
  <pre><code>----+------------------------
      | jsonb_set
      | jsonb
  ----+------------------------
    1 | {"k1": {"value": "v1"}}
  ----+------------------------
  </code></pre>
  
  <p>I was expecting <code>{"k1": {"value": "v1"}, "k2": {"value": "v2"}}</code>
  I also tried <code>FALSE</code> as the fourth parameter in case it was reversed or something.</p>
  
  <p>I am using PostgreSQL 9.6.4</p>