From 30bab91a6890f55dd8d4516b97f46304262280ed Mon Sep 17 00:00:00 2001
From: Arthur Vickers <ajcvickers@hotmail.com>
Date: Sun, 18 Aug 2019 17:38:52 -0700
Subject: [PATCH] Throw if defining query is used on keyed entity type

Fixes #17157
---
 src/EFCore/Infrastructure/ModelValidator.cs   | 32 +++++++++++++++----
 src/EFCore/Properties/CoreStrings.Designer.cs |  8 +++++
 src/EFCore/Properties/CoreStrings.resx        |  3 ++
 .../Infrastructure/ModelValidatorTest.cs      |  9 ++++++
 .../Metadata/Internal/EntityTypeTest.cs       |  3 --
 5 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/src/EFCore/Infrastructure/ModelValidator.cs b/src/EFCore/Infrastructure/ModelValidator.cs
index ce4b85d35fd..a48536fa859 100644
--- a/src/EFCore/Infrastructure/ModelValidator.cs
+++ b/src/EFCore/Infrastructure/ModelValidator.cs
@@ -72,6 +72,7 @@ public virtual void Validate(IModel model, IDiagnosticsLogger<DbLoggerCategory.M
             ValidateFieldMapping(model, logger);
             ValidateKeylessTypes(model, logger);
             ValidateQueryFilters(model, logger);
+            ValidateDefiningQuery(model, logger);
             ValidateData(model, logger);
             LogShadowProperties(model, logger);
         }
@@ -828,13 +829,32 @@ protected virtual void ValidateQueryFilters([NotNull] IModel model, [NotNull] ID
 
             foreach (var entityType in model.GetEntityTypes())
             {
-                if (entityType.GetQueryFilter() != null)
+                if (entityType.GetQueryFilter() != null
+                    && entityType.BaseType != null)
                 {
-                    if (entityType.BaseType != null)
-                    {
-                        throw new InvalidOperationException(
-                            CoreStrings.BadFilterDerivedType(entityType.GetQueryFilter(), entityType.DisplayName()));
-                    }
+                    throw new InvalidOperationException(
+                        CoreStrings.BadFilterDerivedType(entityType.GetQueryFilter(), entityType.DisplayName()));
+                }
+            }
+        }
+
+        /// <summary>
+        ///     Validates the mapping/configuration of defining queries in the model.
+        /// </summary>
+        /// <param name="model"> The model to validate. </param>
+        /// <param name="logger"> The logger to use. </param>
+        protected virtual void ValidateDefiningQuery(
+            [NotNull] IModel model, [NotNull] IDiagnosticsLogger<DbLoggerCategory.Model.Validation> logger)
+        {
+            Check.NotNull(model, nameof(model));
+
+            foreach (var entityType in model.GetEntityTypes())
+            {
+                if (entityType.GetDefiningQuery() != null
+                    && entityType.FindPrimaryKey() != null)
+                {
+                    throw new InvalidOperationException(
+                        CoreStrings.DefiningQueryAndKey(entityType.DisplayName()));
                 }
             }
         }
diff --git a/src/EFCore/Properties/CoreStrings.Designer.cs b/src/EFCore/Properties/CoreStrings.Designer.cs
index 122c6a0b152..c2788bc0e64 100644
--- a/src/EFCore/Properties/CoreStrings.Designer.cs
+++ b/src/EFCore/Properties/CoreStrings.Designer.cs
@@ -1630,6 +1630,14 @@ public static string BadFilterDerivedType([CanBeNull] object filter, [CanBeNull]
                 GetString("BadFilterDerivedType", nameof(filter), nameof(entityType)),
                 filter, entityType);
 
+        /// <summary>
+        ///     The entity type '{entityType}' cannot use 'ToQuery' to create a defining query because it also defines a primary key. Defining queries can only be used to back entity types without keys.
+        /// </summary>
+        public static string DefiningQueryAndKey([CanBeNull] object entityType)
+            => string.Format(
+                GetString("DefiningQueryAndKey", nameof(entityType)),
+                entityType);
+
         /// <summary>
         ///     Converter for model type '{converterType}' cannot be used for '{entityType}.{propertyName}' because its type is '{propertyType}'.
         /// </summary>
diff --git a/src/EFCore/Properties/CoreStrings.resx b/src/EFCore/Properties/CoreStrings.resx
index 925419ea6e3..dc5f1cdd711 100644
--- a/src/EFCore/Properties/CoreStrings.resx
+++ b/src/EFCore/Properties/CoreStrings.resx
@@ -891,6 +891,9 @@
   <data name="BadFilterDerivedType" xml:space="preserve">
     <value>The filter expression '{filter}' cannot be specified for entity type '{entityType}'. A filter may only be applied to the root entity type in a hierarchy.</value>
   </data>
+  <data name="DefiningQueryAndKey" xml:space="preserve">
+    <value>The entity type '{entityType}' cannot use 'ToQuery' to create a defining query because it also defines a primary key. Defining queries can only be used to back entity types without keys.</value>
+  </data>
   <data name="ConverterPropertyMismatch" xml:space="preserve">
     <value>Converter for model type '{converterType}' cannot be used for '{entityType}.{propertyName}' because its type is '{propertyType}'.</value>
   </data>
diff --git a/test/EFCore.Tests/Infrastructure/ModelValidatorTest.cs b/test/EFCore.Tests/Infrastructure/ModelValidatorTest.cs
index 0ef7e9c682b..189540294af 100644
--- a/test/EFCore.Tests/Infrastructure/ModelValidatorTest.cs
+++ b/test/EFCore.Tests/Infrastructure/ModelValidatorTest.cs
@@ -31,6 +31,15 @@ public virtual void Detects_filter_on_derived_type()
             VerifyError(CoreStrings.BadFilterDerivedType(entityTypeD.GetQueryFilter(), entityTypeD.DisplayName()), modelBuilder.Model);
         }
 
+        [ConditionalFact]
+        public virtual void Detects_defining_query_on_keyed_entity_type()
+        {
+            var modelBuilder = CreateConventionalModelBuilder();
+            modelBuilder.Entity<A>().ToQuery(() => new List<A>().AsQueryable());
+
+            VerifyError(CoreStrings.DefiningQueryAndKey("A"), modelBuilder.Model);
+        }
+
         [ConditionalFact]
         public virtual void Detects_shadow_entities()
         {
diff --git a/test/EFCore.Tests/Metadata/Internal/EntityTypeTest.cs b/test/EFCore.Tests/Metadata/Internal/EntityTypeTest.cs
index cf50680d7a5..c1eb9c2c974 100644
--- a/test/EFCore.Tests/Metadata/Internal/EntityTypeTest.cs
+++ b/test/EFCore.Tests/Metadata/Internal/EntityTypeTest.cs
@@ -65,12 +65,9 @@ private class FakeEntityType : IEntityType
             public string Name { get; }
             public Type ClrType { get; }
             public IEntityType BaseType { get; }
-            public bool IsKeyless { get; }
             public string DefiningNavigationName { get; }
             public IEntityType DefiningEntityType { get; }
             public LambdaExpression QueryFilter { get; }
-            public LambdaExpression DefiningQuery { get; }
-            public bool IsQueryType { get; }
             public IKey FindPrimaryKey() => throw new NotImplementedException();
             public IKey FindKey(IReadOnlyList<IProperty> properties) => throw new NotImplementedException();
             public IEnumerable<IKey> GetKeys() => throw new NotImplementedException();