title: U- SQL Unable to extract data from JSON file
body: <p>I was trying to extract data from a JSON file using USQL. Either the query runs successfully without producing any output data or results in "vertex failed fast error".</p>
  
  <p>The JSON file looks like:</p>
  
  <pre class="lang-js prettyprint-override"><code>{
    "results": [
      {
        "name": "Sales/Account",
        "id": "7367e3f2-e1a5-11e5-80e8-0933ecd4cd8c",
        "deviceName": "HP",
        "deviceModel": "g6-pavilion",
        "clientip": "0.41.4.1"
      },
      {
        "name": "Sales/Account",
        "id": "c01efba0-e0d5-11e5-ae20-af6dc1f2c036",
        "deviceName": "acer",
        "deviceModel": "veriton",
        "clientip": "10.10.14.36"
      }
    ]
  }
  </code></pre>
  
  <p>And my U-SQL script is</p>
  
  <pre><code>REFERENCE ASSEMBLY [Newtonsoft.Json];
  REFERENCE ASSEMBLY [Microsoft.Analytics.Samples.Formats];
  
  DECLARE @in string="adl://xyz.azuredatalakestore.net/todelete.json";
  
  DECLARE @out string="adl://xyz.azuredatalakestore.net/todelete.tsv";
  
  @trail2=EXTRACT results string FROM @in USING new Microsoft.Analytics.Samples.Formats.Json.JsonExtractor();
  
  @jsonify=SELECT Microsoft.Analytics.Samples.Formats.Json.JsonFunctions.JsonTuple(results,"name","id","deviceName","deviceModel","clientip") AS rec FROM @trail2;
  
  @logSchema=SELECT rec["name"] AS sysName,
                rec["id"] AS sysId,
                rec["deviceName"] AS domainDeviceName,
                rec["deviceModel"] AS domainDeviceModel,
                rec["clientip"] AS domainClientIp 
         FROM @jsonify;
  
  OUTPUT @logSchema TO @out USING Outputters.Tsv();
  </code></pre>