Unable to add relationship between feature layer and table in Portal

[carloniluca91]

Describe the bug
Hi,
i'm using arcgis version 2.4.1.1 and authenticating to an on-premise portal. By following the example in this post, https://community.esri.com/t5/arcgis-api-for-python-blog/add-table-from-hosted-service-to-another-and/bc-p/1647390, i can't add relationships between the feature layer and the table.
To be precise, the statement causing the program to fail is

lyr.manager.add_to_definition({"relationships": [lyr_rel_dict]})

The error message is poor

Exception: {'code': 500, 'message': "Field 'relationships' cannot be updated.", 'details': []}

Unfortunately, none of the comments within the post helps

Platform

• OS: Windows 11
• Python API Version: 2.4.1.1
• Python version: 3.12.11

[nanaeaubry]

@carloniluca91 We will take a look at this but it is not a workflow we are familiar with. Can you give some more info about whether you have tried this in the past on layers and it worked or if this is the first time?

Also, is the goal that you have a table and you want to add it to an existing feature service? Is that correct? If so, you might be able to use the insert_layer method instead. See: https://developers.arcgis.com/python/latest/api-reference/arcgis.features.managers.html#arcgis.features.managers.FeatureLayerCollectionManager.insert_layer

[carloniluca91]

@nanaeaubry
In my workflow I successfully created a hosted feature service using
fc = gis.content.create_service(...)

and then successfully added a definition (containing a feature layer and a table) to this service using
fc.manager.add_to_definition(...)

In addition to these steps, I also wanted to add a relationship between the feature layer and the table by adding a relationship definition to the layer. I tried to define the relationship as follows

stores_traffic_rel_definition = { "id": 0, "name": "stores_to_traffic", "relatedTableId": 1, "role": "esriRelRoleOrigin", "keyField": "key_store", "cardinality": "esriRelCardinalityOneToOne", "composite": False }

and then tried to add it to the layer definition using
stores_layer.manager.add_to_definition( { "relationships": [stores_traffic_rel_definition] } )

(stores_layer is the reference to the feature layer)

However, when doing so, I always got the following error

Exception: {'code': 500, 'message': "Field 'relationships' cannot be updated.", 'details': []}

Some details

• i'm connecting to a GIS enterprise (portal) version 11.3
• i'm using arcgis library version 2.4.1.1 and Python 3.12
• OS: Windows 11

Actually this was my first attempt to define a relationship using the arcgis Python API. Previously, I managed to do that by hand using ARCGIS Pro Desktop application, and publishing a non-hosted map image layer (not a hosted feature service). I was trying to automate the process via code.

Hoe it helps ;)

P.S I tried to accomplish the same result (creating an hosted feature service defining a relationship) using the ARCGIS desktop app, apparently relationships are not supported for this kind of items, as I'm getting the following warning

24040: In-memory relates are not supported
and, even if the service is published, relationships do not appear. On the other hand, relationships appear when publishing non-hosted map image. Do you know if relationships are not supported at all for hosted feature services ?

[nanaeaubry]

The person who wrote this guide posted this as well in response to someone who had the same problem: https://community.esri.com/t5/arcgis-api-for-python-questions/relate-a-hosted-table-and-feature-layer-arcgis/td-p/1479738

[Clubdebambos]

I tested this in Portal this evening. The workflow only works in ArcGIS Online. I get the same error when using Portal: Exception: Field 'relationships' cannot be updated. I would say that this is a bug for adding relationships to hosted feature services in Portal via the ArcGIS API for Python.

[nanaeaubry]

Thanks we will take note of this and look for solutions.

cc @ManushiM Can you triage and open an issue?

[carloniluca91]

hi guys, any update on this ?