Cannot add a vertex where the partition key property has value 'null'

[Evan]

Describe the bug
Not sure how to set the partition key when creating a Vertex, error: "Cannot add a vertex where the partition key property has value 'null'". Getting data works fine.

Expected behavior
To add a vertex in my cosmos db

Version information
prerelease 8.0.0-preview-0707

Minimal working example
setup
_g = g.ConfigureEnvironment(env => env
.UseModel(GraphModel
.FromBaseTypes<Vertex, Edge>(lookup => lookup
.IncludeAssembliesOfBaseTypes())
.ConfigureProperties(model => model
.ConfigureElement(conf => conf
.IgnoreOnUpdate(x => x.TenantId))))
.UseCosmosDb(builder => builder
.At(uri, databaseName, graphName)
.AuthenticateBy(authKey)
.ConfigureWebSocket(builder => builder)));
.ConfigureQueryLoggingOptions(o => o
.SetQueryLoggingVerbosity(QueryLoggingVerbosity.None)))));

public class Person: Vertex
{
    public string TenantId { get; set; }
    public int Age { get; set; }
}
public class Vertex : IVertex
{
    public object Id { get; set; }
    public string Label { get; set; }
    public string TenantId { get; set; } = "TenantId";
}

      var _marko = await _g
                 .AddV(new Person { TenantId = "tenID", Age = 29,  })
                 .FirstAsync();

[Daniel Weber]

Vertices in CosmosDB must have a PartitionKey property.

Have a look how it's done in the samples, especially here and here.

[Evan]

I've seen the example but I can't figure it out.
my pk is /tenantId

Does this mean I have to change the Vertex class

` public string PartitionKey { get; set; } = "TenantId"; `

or
public string PartitionKey { get; set; } = "/tenantId";
or
public string TenantId { get; set; } = "PartitionKey";

or do I not inherit van Vertex
and just create

public string PartitionKey { get; set; } = "TenantId"; in my Person class

Do I still need to create a new object in AddV or can I just pass an existing object

????!???!???

[Daniel Weber]

You can pass in existing objects, it just needs a PartitionKey property with a value of your choice. It's just a property after all. Having the property on the base class of all vertices is a good choice.

See also https://docs.microsoft.com/en-us/azure/cosmos-db/partitioning-overview

EDIT: I see the issue. Yes, of course the property in C# must be accordingly named. In your case, "tenantId". Casing is probably significant as well.

[Evan]

Issue solved, its a casing issue.
Thank you very much for your time.