title: postgres GENERATED ALWAYS jsonb with refers to other columns inside a string
body: <p>Trying to generate a jsonb column that will look like this:
  <code>[&quot;c:cluster-x&quot;, &quot;ns:cluster-x/namespace-1&quot;]</code></p>
  <p>The cluster and namespace will be taken from other fields. I'm struggling with finding a way to concat it successfully</p>
  <p>Also an array literal will be fine here, like this <code>'{c:cluster-x, ns:cluster-x/namespace-1}'</code></p>
  <p>I tried something like this:</p>
  <pre><code>ALTER TABLE my_table ADD COLUMN resources jsonb GENERATED ALWAYS AS ('[&quot;c:&quot;' || my_table.&quot;clusterName&quot; || ']'::jsonb) STORED;
  </code></pre>
  <p>but getting:
  <code>Detail: Expected JSON value, but found &quot;]&quot;.</code></p>
  <p>postgres version 13.4</p>