title: JSON Schema for tree structure
body: <p>I have to build tree like structure of Json data.Each node has an id (an integer, required), a label (a string, optional), and an array of child nodes (optional). Can you help me how to write JSON schema for this Json data. I need to set Id as required in child node as well. </p>
  
  <pre><code>{
      "Id": 1,
      "Label": "A",
      "Child": [
          {
              "Id": 2,
              "Label": "B",
              "Child": [
                  {
                      "Id": 5,
                      "Label": "E"
                  }, {
                      "Id": 6,
                      "Label": "E"
                  }, {
                      "Id": 7,
                      "Label": "E"
                  }
              ]
          }, {
              "Id": 3,
              "Label": "C"
          }, {
              "Id": 4,
              "Label": "D",
              "Child": [
                  {
                      "Id": 8,
                      "Label": "H"
                  }, {
                      "Id": 9,
                      "Label": "I"
                  }
              ]
          }
      ]
  }
  </code></pre>
  
  <p><a href="http://i.stack.imgur.com/i9le2.png" rel="nofollow">enter image description here</a></p>