# API: Invalid Raw Reflection, Must Have at least one DIsplay Field

**URL:** <https://community.dremio.com/t/api-invalid-raw-reflection-must-have-at-least-one-display-field/3718>\
**Category:** Uncategorized\
**Created:** [July 19, 2019, 9:24pm UTC](https://community.dremio.com/t/api-invalid-raw-reflection-must-have-at-least-one-display-field/3718 "2019-07-19T21:24:39Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![tonio](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/tonio/32/1680_2.png) [@tonio](https://community.dremio.com/u/tonio)\
**Post date:** [July 19, 2019, 9:24pm UTC](https://community.dremio.com/t/api-invalid-raw-reflection-must-have-at-least-one-display-field/3718/1 "2019-07-19T21:24:39Z")

</div>

HI, I was trying to create a Raw reflection on a Promoted PDS using dremio’s api.

I promote the file to a PDS, I get this response:

```auto
{'entityType': 'dataset',
 'id': 'AAAAAAAAA-AAAAAAAAA-AAAAAA-AAAAAAA',
 'type': 'PHYSICAL_DATASET',
 'path': ['DremioS3Source',
  'JJJJJJJ',
  'ZZZZZZZ',
  'XXXX',
  'YYYYY'],
 'createdAt': '2019-07-19T20:44:52.927Z',
 'tag': '0',
 'format': {'type': 'Parquet',
  'ctime': 0,
  'isFolder': True,
  'location': '/JJJJJJJ/ZZZZZZZ/XXXX/YYYYY',
  'autoCorrectCorruptDates': True},
 'approximateStatisticsAllowed': False,
 'fields': [{'name': 'a', 'type': {'name': 'VARCHAR'}},
  {'name': 'b', 'type': {'name': 'VARCHAR'}},
  {'name': 'c', 'type': {'name': 'TIMESTAMP'}},
  {'name': 'd', 'type': {'name': 'TIMESTAMP'}},
  {'name': 'e', 'type': {'name': 'VARCHAR'}},
  {'name': 'f', 'type': {'name': 'VARCHAR'}},
  {'name': 'g', 'type': {'name': 'VARCHAR'}},
  {'name': 'h', 'type': {'name': 'INTEGER'}},
  {'name': 'i', 'type': {'name': 'TIMESTAMP'}}]}

```

Then I pass the body of data below to create the reflection:

```auto
{
  "entityType": "reflection", 
  "name": 'YYYYYY-raw', 
  "enabled": True, 
  "type": 'RAW', 
  "datasetId": 'AAAAAAAAA-AAAAAAAAA-AAAAAA-AAAAAAA',
  "partitionDistributionStrategy": 'CONSOLIDATED' }

```

Then I get the following error:

```auto
{'errorMessage': 'Invalid reflection: raw reflection must have at least one display field configured',
 'context': [],
 'moreInfo': ''}

```

In the [Documentation](https://docs.dremio.com/rest-api/reflections/post-reflection.html) you say that the ‘displayFields’ is optional, which is not the case, but ok… not a big deal.

So then, I thought about passing the keys I got from the response as values on the reflection creation.

```auto
{
  "entityType": "reflection", 
  "name": 'YYYYYY-raw', 
  "enabled": True, 
  "type": 'RAW', 
  "datasetId": 'AAAAAAAAA-AAAAAAAAA-AAAAAA-AAAAAAA',
  "displayFields": pds_creation_response['fields'],
  "partitionDistributionStrategy": 'CONSOLIDATED' }

```

Then I got the following error:

```auto
'Unrecognized field "type" (class com.dremio.service.reflection.proto.ReflectionField), not marked as ignorable (one known property: "name"])
 at [Source: (org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream); line: 1, column: 187] (through reference chain: com.dremio.dac.api.Reflection["displayFields"]->java.util.ArrayList[0]->com.dremio.service.reflection.proto.ReflectionField["type"])'

```

So, on what exact syntax should I pass in “displayFields”?  
Would I need make a clumsy for loop to extract just the names of the fields?  
Is there another way to do it?

---

<div class="post-metadata">

**Author:** ![doron](https://sea2.discourse-cdn.com/flex020/user_avatar/community.dremio.com/doron/32/294_2.png) [@doron](https://community.dremio.com/u/doron)\
**Post date:** [July 22, 2019, 11:29pm UTC](https://community.dremio.com/t/api-invalid-raw-reflection-must-have-at-least-one-display-field/3718/2 "2019-07-22T23:29:12Z")

</div>

The payload should look like this:

```json
{
  "type":"RAW",
  "name":"Raw Reflection",
  "enabled":true,
  "partitionDistributionStrategy":"CONSOLIDATED",
  "displayFields": [
    {"name":"IncidntNum"}
  ],
  "datasetId":"d156ccaf-d0eb-4693-b9db-51d2f8af44bf"
}

```

It looks like you are adding a `type` field to each field entry.