title: Curl and Odata filter: Invalid filter expression
body: <p>I need to apply a OData filter in a curl request like this one</p>
  
  <pre><code>curl -k -H "Authorization: Bearer d_fkI7fEPSz9z8RmaGklFWeuPp4a" -v 'https://api.smartdatanet.it/api/Deploy_confi_3790/DataEntities?&amp;$format=json&amp;$top=15&amp;$filter=Ide_id eq 2071)'
  </code></pre>
  
  <p>The service respond in  Json format like this one</p>
  
  <pre><code>            "internalId": "5c50c7e97f3a377c2431e8cf",
              "datasetVersion": 1,
              "idDataset": "3790",
              "Id_unita_install": 52709,
              "Progressivo": "2",
              "Tipo_udd": "Unità di config",
              "Id_istanza": 1347,
              "Id_middleware": 4,
              "Middleware": "Apache WebServer",
              "Vers_middleware": "2.2.31",
              "Ambiente": "COLL",
              "Partizione": null,
              "Dominio": null,
              "Valore": "naocli/naocli8",
              "Ide_id": 2071
  </code></pre>
  
  <p>... so the Ide_id field exist and has numbers inside.</p>
  
  <p>When I try to execute the error is:</p>
  
  <pre><code>{"error":{"code":null,"message":{"lang":"en","value":"Invalid filter expression: 'Ide_id'."}}}
  </code></pre>
  
  <p>Any suggestions is appreciated!</p>