PartitionKey value must be supplied for this operation in CosmosDB delete operation using DocumentClient

Question

I am trying to delete an item from a container of Cosmos DB database from azure function. But I am getting this error PartitionKey value must be supplied for this operation. I also investigated this but didn't get any luck from there.

Below is my code -

public class Item{
    public Item(){}
    public string id {get; set;}
}

public static async Task<IActionResult> Run(HttpRequest req, ILogger log)
{
    DocumentClient client = new DocumentClient(new Uri("https://***.documents.azure.com:443/"), Environment.GetEnvironmentVariable("key"));

    string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
    var updated = JsonConvert.DeserializeObject<Item>(requestBody);
    
    var option = new FeedOptions { EnableCrossPartitionQuery = true };
    var collectionUri = UriFactory.CreateDocumentCollectionUri("Test_DB", "Test_Table");
  
    var document = client.CreateDocumentQuery(collectionUri, option).Where(t => t.Id == updated.id)
        .AsEnumerable().FirstOrDefault();

    log.LogInformation("Total Incentive : " + document.GetPropertyValue<string>("id"));

    if (document == null)
    {
        return new NotFoundResult();
    }

    log.LogInformation("Total Incentive : " + document.SelfLink);
    log.LogInformation("Total Incentive : " + document.Id);

    await client.DeleteDocumentAsync(document.SelfLink);
  
    //await client.ReplaceDocumentAsync(document);

    return new OkObjectResult("Deleted");
}

After googling I realized that I need to provide a partition key value as the second parameter in DeleteDocumentAsync() like below. But I am in a fix how to provide that partition key value to that function.

await client.DeleteDocumentAsync(document.SelfLink,
  new Requestoptions
  {
    PartitionKey = new Microsoft.Azure.Documents.PartitionKey("33333")
  }
)

DB Name: Test_DB

Table Name: Test_Table

Partition Key: /testCategory

An example element of my Test_Table which I am trying to delete is:

{
    "id": "3f614t4e-q85f-4357-8393-a0b3542db4e1",
    "Email": "[email protected]",
    "Name": "Test User",
    "_rid": "XNMBANxVc8oIAAAAAAAAAA==",
    "_self": "dbs/XNMOXA==/colls/TNMNANyVc9o=/docs/XNMBANxVc8oIZZAAAAAAPP==/",
    "_etag": "\"450031d4-0000-0300-0000-60cb36470000\"",
    "_attachments": "attachments/",
    "_ts": 1623930439
}

Can anyone help me how to put that partition key in the azure function code? Or how to adjust the table of the database?

Thanks In Advance.

Answer 1

As mentioned in the comment, when the partition key is not specified in the document, you can use Microsoft.Azure.Documents.PartitionKey.None as partition key value for deletes and updates.

In Cosmos DB, each document must have a value specified for the partition key attribute (testCategory in your case) when you create a document. However, Cosmos DB will not complain if you don't specify a value. It simply puts such documents in a special partition that can be accessed by specifying Microsoft.Azure.Documents.PartitionKey.None in the methods where you need it.