Don't persist keys for embedded entities

src/EFCore.Cosmos/Extensions/CosmosDbContextOptionsExtensions.cs

@@ -23,7 +23,7 @@ public static class CosmosDbContextOptionsExtensions
         /// <param name="accountEndpoint"> The account end-point to connect to. </param>
         /// <param name="accountKey"> The account key. </param>
         /// <param name="databaseName"> The database name. </param>
-        /// <param name="cosmosOptionsAction">An optional action to allow additional Cosmos-specific configuration.</param>
+        /// <param name="cosmosOptionsAction"> An optional action to allow additional Cosmos-specific configuration. </param>
         /// <returns> The options builder so that further configuration can be chained. </returns>
         public static DbContextOptionsBuilder<TContext> UseCosmos<TContext>(
             [NotNull] this DbContextOptionsBuilder<TContext> optionsBuilder,
@@ -46,7 +46,7 @@ public static DbContextOptionsBuilder<TContext> UseCosmos<TContext>(
         /// <param name="accountEndpoint"> The account end-point to connect to. </param>
         /// <param name="accountKey"> The account key. </param>
         /// <param name="databaseName"> The database name. </param>
-        /// <param name="cosmosOptionsAction">An optional action to allow additional Cosmos-specific configuration.</param>
+        /// <param name="cosmosOptionsAction"> An optional action to allow additional Cosmos-specific configuration. </param>
         /// <returns> The options builder so that further configuration can be chained. </returns>
         public static DbContextOptionsBuilder UseCosmos(
             [NotNull] this DbContextOptionsBuilder optionsBuilder,

src/EFCore.Cosmos/Extensions/CosmosPropertyExtensions.cs

@@ -1,6 +1,7 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
+using System.Linq;
 using JetBrains.Annotations;
 using Microsoft.EntityFrameworkCore.Cosmos.Metadata.Internal;
 using Microsoft.EntityFrameworkCore.Metadata;
@@ -20,7 +21,27 @@ public static class CosmosPropertyExtensions
         /// <returns> The property name used when targeting Cosmos. </returns>
         public static string GetCosmosPropertyName([NotNull] this IProperty property) =>
             (string)property[CosmosAnnotationNames.PropertyName]
-            ?? property.Name;
+            ?? GetDefaultPropertyName(property);
+
+        private static string GetDefaultPropertyName(IProperty property)
+        {
+            var entityType = property.DeclaringEntityType;
+            var ownership = entityType.FindOwnership();
+
+            if (ownership != null
+                && !entityType.IsDocumentRoot())
+            {
+                var pk = property.FindContainingPrimaryKey();
+                if (pk != null
+                    && pk.Properties.Count == ownership.Properties.Count + (ownership.IsUnique ? 0 : 1)
+                    && ownership.Properties.All(fkProperty => pk.Properties.Contains(fkProperty)))
+                {
+                    return "";
+                }
+            }
+
+            return property.Name;
+        }
 
         /// <summary>
         ///     Sets the property name used when targeting Cosmos.

src/EFCore.Cosmos/Extensions/CosmosServiceCollectionExtensions.cs

@@ -9,12 +9,14 @@
 using Microsoft.EntityFrameworkCore.Cosmos.Metadata.Conventions.Internal;
 using Microsoft.EntityFrameworkCore.Cosmos.Query.Internal;
 using Microsoft.EntityFrameworkCore.Cosmos.Storage.Internal;
+using Microsoft.EntityFrameworkCore.Cosmos.ValueGeneration.Internal;
 using Microsoft.EntityFrameworkCore.Diagnostics;
 using Microsoft.EntityFrameworkCore.Infrastructure;
 using Microsoft.EntityFrameworkCore.Metadata.Conventions.Infrastructure;
 using Microsoft.EntityFrameworkCore.Query;
 using Microsoft.EntityFrameworkCore.Storage;
 using Microsoft.EntityFrameworkCore.Utilities;
+using Microsoft.EntityFrameworkCore.ValueGeneration;
 
 // ReSharper disable once CheckNamespace
 namespace Microsoft.Extensions.DependencyInjection
@@ -53,6 +55,7 @@ public static IServiceCollection AddEntityFrameworkCosmos([NotNull] this IServic
                 .TryAdd<IDbContextTransactionManager, CosmosTransactionManager>()
                 .TryAdd<IModelValidator, CosmosModelValidator>()
                 .TryAdd<IProviderConventionSetBuilder, CosmosConventionSetBuilder>()
+                .TryAdd<IValueGeneratorSelector, CosmosValueGeneratorSelector>()
                 .TryAdd<IDatabaseCreator, CosmosDatabaseCreator>()
                 .TryAdd<IQueryContextFactory, CosmosQueryContextFactory>()
                 .TryAdd<ITypeMappingSource, CosmosTypeMappingSource>()

src/EFCore.Cosmos/Metadata/Conventions/StoreKeyConvention.cs

@@ -9,15 +9,16 @@
 using Microsoft.EntityFrameworkCore.Utilities;
 using Newtonsoft.Json.Linq;
 
+// ReSharper disable once CheckNamespace
 namespace Microsoft.EntityFrameworkCore.Metadata.Conventions
 {
     /// <summary>
     ///     <para>
     ///         A convention that adds the 'id' property - a key required by Azure Cosmos.
     ///     </para>
-    ///         This convention also add the '__jObject' containing the JSON object returned by the store.
     ///     <para>
-    /// </para>
+    ///         This convention also adds the '__jObject' containing the JSON object returned by the store.
+    ///     </para>
     /// </summary>
     public class StoreKeyConvention :
         IEntityTypeAddedConvention,
@@ -52,10 +53,6 @@ private static void Process(IConventionEntityTypeBuilder entityTypeBuilder)
                 var idProperty = entityTypeBuilder.Property(typeof(string), IdPropertyName);
                 idProperty.HasValueGenerator((_, __) => new IdValueGenerator());
                 entityTypeBuilder.HasKey(new[] { idProperty.Metadata });
-
-                var jObjectProperty = entityTypeBuilder.Property(typeof(JObject), JObjectPropertyName);
-                jObjectProperty.ToJsonProperty("");
-                jObjectProperty.ValueGenerated(ValueGenerated.OnAddOrUpdate);
             }
             else
             {
@@ -68,7 +65,17 @@ private static void Process(IConventionEntityTypeBuilder entityTypeBuilder)
                         entityType.Builder.HasNoKey(key);
                     }
                 }
+            }
 
+            if (entityType.BaseType == null
+                && !entityType.IsKeyless)
+            {
+                var jObjectProperty = entityTypeBuilder.Property(typeof(JObject), JObjectPropertyName);
+                jObjectProperty.ToJsonProperty("");
+                jObjectProperty.ValueGenerated(ValueGenerated.OnAddOrUpdate);
+            }
+            else
+            {
                 var jObjectProperty = entityType.FindDeclaredProperty(JObjectPropertyName);
                 if (jObjectProperty != null)
                 {

src/EFCore.Cosmos/Metadata/Internal/CosmosEntityTypeExtensions.cs

@@ -1,8 +1,6 @@
 // Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
-using JetBrains.Annotations;
-using Microsoft.EntityFrameworkCore.Cosmos.Storage.Internal;
 using Microsoft.EntityFrameworkCore.Metadata;
 
 namespace Microsoft.EntityFrameworkCore.Cosmos.Metadata.Internal
@@ -25,22 +23,5 @@ public static bool IsDocumentRoot(this IEntityType entityType)
             => entityType.BaseType?.IsDocumentRoot()
                 ?? (!entityType.IsOwned()
                     || entityType[CosmosAnnotationNames.ContainerName] != null);
-
-        /// <summary>
-        ///     This is an internal API that supports the Entity Framework Core infrastructure and not subject to
-        ///     the same compatibility standards as public APIs. It may be changed or removed without notice in
-        ///     any release. You should only use it directly in your code with extreme caution and knowing that
-        ///     doing so can result in application failures when updating to a new Entity Framework Core release.
-        /// </summary>
-        public static string GetCosmosPartitionKeyStoreName([NotNull] this IEntityType entityType)
-        {
-            var name = entityType.GetCosmosPartitionKeyPropertyName();
-            if (name != null)
-            {
-                return entityType.FindProperty(name).GetCosmosPropertyName();
-            }
-
-            return CosmosClientWrapper.DefaultPartitionKey;
-        }
     }
 }

src/EFCore.Cosmos/Query/Internal/CosmosProjectionBindingExpressionVisitor.cs

@@ -200,7 +200,8 @@ protected override Expression VisitMember(MemberExpression memberExpression)
                     throw new InvalidOperationException();
             }
 
-            var navigationProjection = innerEntityProjection.BindMember(memberExpression.Member, innerExpression.Type, out var propertyBase);
+            var navigationProjection = innerEntityProjection.BindMember(
+                memberExpression.Member, innerExpression.Type, clientEval: true, out var propertyBase);
 
             if (!(propertyBase is INavigation navigation)
                 || !navigation.IsEmbedded())