title: I can not extract data from a JSON type column in PostgreSQL
body: <p>I want to extract data from a json type column to insert them into a table in order to normalize a database.</p>
  
  <p>The JSON type column is called "info" and an example of a record is the following:</p>
  
  <pre><code>[ { "major" : "International business", 
      "end" : "2007", 
      "name" : "Annamalai University",
      "degree" : "Master Degree", 
      "start" : "2005", "desc" : "" 
    }, 
    { "major" : "Mechanical Engineering", 
      "end" : "1990", 
      "name" : "Bharathidasan University", 
      "degree" : "Bachelor Degree", 
      "start" : "1990", "desc" : "" 
    }
  ]
  </code></pre>
  
  <p>This is my code:</p>
  
  <pre><code>SELECT id,
         (json_array_elements(info)-&gt;&gt;'education')::json -&gt;&gt; 'key' AS key1 
  FROM perfiles
  WHERE id = 1252710;
  </code></pre>
  
  <p>This is the result I want to obtain:
  <a href="https://i.stack.imgur.com/zLxV6.jpg" rel="nofollow noreferrer">table result example</a></p>
  
  <p>How should I do the query?</p>
  
  <p>Thanks in advance</p>