带有现有CosmosDB 404错误的实体框架核心

Question

public class dbcontext:DbContext
{
    public DbSet<entity1> entities1 { get; set; }

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        optionsBuilder.UseCosmos(
          "https://localhost:8081",
          "C2y6yDjf5/R+ob0N8A7Cgv30VRDJIWEHLM+4QDU5DE2nQ9nDuVTqobD4b8mGGyPMbIZnqyMsEcaGQy67XIw/Jw==",
          "myDocuments");
    }

    public class entity1
    {
        [Key]
        public string id { get; set; }

        public string name { get; set; }
    }

  }

Below error when trying to create a document.. using Microsoft.EntityFrameworkCore.Cosmos Preview3 and cosmos emulator

Answer 1

I think the reason for this is the preview nature of the Cosmos DB provider. I was having the same issue. I'd pre-created my collection using the storage emulator which requires you to define a partition key. Note that there is no notion of a "partition key" with the preview Cosmos provider. That's a huge problem for Cosmos DB. However the emulator appears to be fairly resilient.

If you do as Nick Chapsas suggests and make a call to context.Database.EnsureCreated you should see a new collection has been created in the emulator. If you look at the new collection's Scale & Settings you'll find no partition key. Partition key is a required field when creating a new collection. The preview provider appears to be creating collections that are not valid. The emulator seems to be OK with that but Azure Cosmos DB is not.