title: Postgres query to convert stringifyed json object to jsonb object
body: <p>let say that the json object is > { "foo": "bar"}
  after stringyfing i got > "{ \"foo\": \"bar\" }"</p>
  
  <p>how can I get back the orginal json object using UPDATE sql query?</p>
  
  <p><a href="https://i.stack.imgur.com/eDMSN.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/eDMSN.png" alt="enter image description here"></a></p>
  
  <p>i'm aware of that it's a bad DB architecture it was designed by another engineer before me, that's why I would like get back the original json data and then alter the column to jsonb</p>
  
  <p><strong>Update:</strong> 
  please be aware that I'm looking for an answer to do that with only sql query and without any involving of programming languages like javascript.. etc</p>