Field of custom database view not visible in REST API results

Hi,

We are planning to use a view to provide interface for reading data over REST API. We configured a mockup-view and set permissions and it's possibly to query the view over the REST API, but it only returns the uid_person column. If we include any other columns to as DisplayColumns-arguments, they are not shown in the result and we haven't yet been able to find the reason.

Query for the view:

select uid_person, personnelnumber, DefaultEmailAddress, XDateInserted, XDateUpdated, XObjectKey from person

REST-call:
curl -X GET "">localhost/.../CCC_if_test_single_02 -H  "accept: application/json"

Result:

[
  {
    "uri": "/iamapp/api/entity/CCC_if_test_single_02/1a2a0ff8-2d7c-450e-8fcb-88503efa2cef",
    "display": "1a2a0ff8-2d7c-450e-8fcb-88503efa2cef",
    "longDisplay": "1a2a0ff8-2d7c-450e-8fcb-88503efa2cef",
    "values": {
      "uid_person": "1a2a0ff8-2d7c-450e-8fcb-88503efa2cef"
    }
  },
  {
    "uri": "/iamapp/api/entity/CCC_if_test_single_02/9fa4fe04-f94d-43d0-a233-4fe20ce5021d",
    "display": "9fa4fe04-f94d-43d0-a233-4fe20ce5021d",
    "longDisplay": "9fa4fe04-f94d-43d0-a233-4fe20ce5021d",
    "values": {
      "uid_person": "9fa4fe04-f94d-43d0-a233-4fe20ce5021d"
    }
  },
 ]

Any suggestions are appreciated. Perhaps we have overlooked some documentation, or maybe this kind of functionality is out of the scope of the REST.