title: How to put variable in JSONB using PostgreSQL?
body: <p>I am doing an example of indexing with JSONB in PostgreSQL and want add random uuid to a piece of JSON like below. However I can't get the syntax just right the closest I have got is <code>"{"lookup_id": " || uuid || "}"</code>.</p>
  
  <pre><code>But I require
  {"lookup_id": "92b3b21a-a87c-1798-5d91-3dbf3043c209"}
  </code></pre>
  
  <p>My code is:</p>
  
  <pre><code>INSERT INTO test (id, json)
  SELECT x.id, '{
      "lookup_id": " || uuid || "
     }'::jsonb 
  FROM generate_series(1,100) AS x(id),
       uuid_in(md5(now()::text)::cstring) AS uuid;
  </code></pre>