Create explicit index object for Keys & ForeignKeys

src/EntityFramework.Commands/Migrations/Design/CSharpSnapshotGenerator.cs

@@ -112,7 +112,7 @@ protected virtual void GenerateEntityType(
 
                     GenerateKeys(entityType.GetDeclaredKeys(), entityType.FindDeclaredPrimaryKey(), stringBuilder);
 
-                    GenerateIndexes(entityType.GetDeclaredIndexes(), stringBuilder);
+                    GenerateIndexes(entityType.GetDeclaredIndexes().Except(entityType.GetKeys().Select(key => key.Index)), stringBuilder);
 
                     GenerateEntityTypeAnnotations(entityType, stringBuilder);
                 }

src/EntityFramework.Core/Metadata/IForeignKey.cs

@@ -46,6 +46,11 @@ public interface IForeignKey : IAnnotatable
         /// </summary>
         INavigation PrincipalToDependent { get; }
 
+        /// <summary>
+        ///     Gets the index object defined on the foreign key properties.
+        /// </summary>
+        IIndex Index { get; }
+
         /// <summary>
         ///     Gets a value indicating whether the values assigned to the foreign key properties are unique.
         /// </summary>

src/EntityFramework.Core/Metadata/IKey.cs

@@ -22,5 +22,10 @@ public interface IKey : IAnnotatable
         ///     may be defined on a base type).
         /// </summary>
         IEntityType DeclaringEntityType { get; }
+
+        /// <summary>
+        ///     Gets the index object defined on the key properties.
+        /// </summary>
+        IIndex Index { get; }
     }
 }

src/EntityFramework.Core/Metadata/IMutableForeignKey.cs

@@ -73,9 +73,14 @@ public interface IMutableForeignKey : IForeignKey, IMutableAnnotatable
         IMutableNavigation HasPrincipalToDependent([CanBeNull] string name);
 
         /// <summary>
-        ///     Gets or sets a value indicating whether the values assigned to the foreign key properties are unique.
+        ///     Gets the index object defined on the foreign key properties.
         /// </summary>
-        new bool? IsUnique { get; set; }
+        new IMutableIndex Index { get; }
+
+        /// <summary>
+        ///     Gets a value indicating whether the values assigned to the foreign key properties are unique.
+        /// </summary>
+        new bool? IsUnique { get; }
 
         /// <summary>
         ///     Gets or sets a value indicating if this relationship is required. If true, the dependent entity must always be

src/EntityFramework.Core/Metadata/IMutableKey.cs

@@ -27,5 +27,10 @@ public interface IMutableKey : IMutableAnnotatable, IKey
         ///     may be defined on a base type).
         /// </summary>
         new IMutableEntityType DeclaringEntityType { get; }
+
+        /// <summary>
+        ///     Gets the index object defined on the key properties.
+        /// </summary>
+        new IMutableIndex Index { get; }
     }
 }

src/EntityFramework.Core/Metadata/Internal/ForeignKey.cs

@@ -96,7 +96,8 @@ public virtual Navigation HasPrincipalToDependent([CanBeNull] string name)
         public virtual EntityType DeclaringEntityType { get; }
         public virtual EntityType PrincipalEntityType { get; }
 
-        public virtual bool? IsUnique { get; set; }
+        public virtual Index Index => DeclaringEntityType.FindIndex(Properties);
+        public virtual bool? IsUnique => Index?.IsUnique;
         protected virtual bool DefaultIsUnique => false;
 
         public virtual bool? IsRequired
@@ -190,6 +191,8 @@ public virtual EntityType ResolveEntityTypeInHierarchy([NotNull] EntityType enti
         IMutableNavigation IMutableForeignKey.PrincipalToDependent => PrincipalToDependent;
         IMutableNavigation IMutableForeignKey.HasPrincipalToDependent(string name) => HasPrincipalToDependent(name);
 
+        IIndex IForeignKey.Index => Index;
+        IMutableIndex IMutableForeignKey.Index => Index;
         bool IForeignKey.IsUnique => IsUnique ?? DefaultIsUnique;
         bool IForeignKey.IsRequired => IsRequired ?? DefaultIsRequired;
         DeleteBehavior IForeignKey.DeleteBehavior => DeleteBehavior ?? DefaultDeleteBehavior;

src/EntityFramework.Core/Metadata/Internal/Index.cs

@@ -3,6 +3,7 @@
 
 using System.Collections.Generic;
 using System.Diagnostics;
+using System.Linq;
 using JetBrains.Annotations;
 using Microsoft.Data.Entity.Utilities;
 
@@ -49,5 +50,7 @@ public virtual ConfigurationSource UpdateConfigurationSource(ConfigurationSource
 
         [UsedImplicitly]
         private string DebuggerDisplay => Property.Format(Properties);
+
+        public virtual bool IsInUse() => (DeclaringEntityType.FindKey(Properties) != null) || DeclaringEntityType.FindForeignKeys(Properties).Any();
     }
 }

src/EntityFramework.Core/Metadata/Internal/InternalEntityTypeBuilder.cs

@@ -86,9 +86,13 @@ public virtual InternalKeyBuilder HasKey([NotNull] IReadOnlyList<PropertyInfo> c
             => HasKey(GetOrCreateProperties(clrProperties, configurationSource), configurationSource);
 
         private InternalKeyBuilder HasKey(IReadOnlyList<Property> properties, ConfigurationSource configurationSource)
-            => properties == null
-                ? null
-                : GetOrAdd(
+        {
+            if (properties == null)
+            {
+                return null;
+            }
+
+            var keyBuilder = GetOrAdd(
                     GetOrCreateProperties(properties, configurationSource),
                     Metadata.FindDeclaredKey,
                     (e, c) => e.UpdateConfigurationSource(c),
@@ -97,6 +101,17 @@ private InternalKeyBuilder HasKey(IReadOnlyList<Property> properties, Configurat
                     configurationSource,
                     onNewKeyAdded: ModelBuilder.ConventionDispatcher.OnKeyAdded);
 
+            if (keyBuilder != null)
+            {
+                ModelBuilder.Entity(keyBuilder.Metadata.DeclaringEntityType.Name, ConfigurationSource.Convention)
+                    .HasIndex(keyBuilder.Metadata.Properties, configurationSource)
+                    .IsUnique(true, configurationSource);
+            }
+
+            return keyBuilder;
+        }
+
+
         public virtual ConfigurationSource? RemoveKey(
             [NotNull] Key key, ConfigurationSource configurationSource, bool canOverrideSameSource = true)
         {
@@ -113,6 +128,11 @@ private InternalKeyBuilder HasKey(IReadOnlyList<Property> properties, Configurat
                 Debug.Assert(removed.HasValue);
             }
 
+            if (key.Index != null)
+            {
+                RemoveIndex(key.Index, configurationSource);
+            }
+
             var removedKey = Metadata.RemoveKey(key.Properties);
             if (removedKey == null)
             {
@@ -600,12 +620,6 @@ private Dictionary<EntityType, List<RelationshipSnapshot>> GroupRelationshipsByT
                 return null;
             }
 
-            foreach (var index in Metadata.GetIndexes().Where(i => i.Properties.Contains(property)).ToList())
-            {
-                var removed = RemoveIndex(index, configurationSource);
-                Debug.Assert(removed.HasValue);
-            }
-
             var detachedRelationships = property.FindContainingForeignKeys().ToList()
                 .Select(DetachRelationship).ToList();
 
@@ -617,6 +631,12 @@ private Dictionary<EntityType, List<RelationshipSnapshot>> GroupRelationshipsByT
                 Debug.Assert(removed.HasValue);
             }
 
+            foreach (var index in Metadata.GetIndexes().Where(i => i.Properties.Contains(property)).ToList())
+            {
+                var removed = RemoveIndex(index, configurationSource);
+                Debug.Assert(removed.HasValue);
+            }
+
             if (Metadata.GetProperties().Contains(property))
             {
                 var removedProperty = Metadata.RemoveProperty(property.Name);
@@ -636,10 +656,11 @@ private RelationshipBuilderSnapshot DetachRelationship([NotNull] ForeignKey fore
             var navigationToPrincipalName = foreignKey.DependentToPrincipal?.Name;
             var navigationToDependentName = foreignKey.PrincipalToDependent?.Name;
             var relationshipBuilder = foreignKey.Builder;
+            var indexBuilder = foreignKey.Index?.Builder;
             var relationshipConfigurationSource = RemoveForeignKey(foreignKey, ConfigurationSource.Explicit, runConventions: false);
             Debug.Assert(relationshipConfigurationSource != null);
 
-            return new RelationshipBuilderSnapshot(relationshipBuilder, navigationToPrincipalName, navigationToDependentName, relationshipConfigurationSource.Value);
+            return new RelationshipBuilderSnapshot(relationshipBuilder, navigationToPrincipalName, navigationToDependentName, indexBuilder, relationshipConfigurationSource.Value);
         }
 
         public virtual ConfigurationSource? RemoveForeignKey([NotNull] ForeignKey foreignKey, ConfigurationSource configurationSource)
@@ -670,7 +691,13 @@ private RelationshipBuilderSnapshot DetachRelationship([NotNull] ForeignKey fore
             var removedForeignKey = Metadata.RemoveForeignKey(foreignKey);
             Debug.Assert(removedForeignKey == foreignKey);
 
-            RemoveShadowPropertiesIfUnused(foreignKey.Properties);
+            var index = foreignKey.Index;
+            if (index != null && !index.IsInUse())
+            {
+                index.DeclaringEntityType.Builder.RemoveIndex(index, configurationSource);
+            }
+
+            RemoveShadowPropertiesIfUnused(foreignKey.Properties.Where(p => p.DeclaringEntityType.FindDeclaredProperty(p.Name) != null).ToList());
             foreignKey.PrincipalKey.DeclaringEntityType.Builder?.RemoveKeyIfUnused(foreignKey.PrincipalKey);
 
             if (runConventions)
@@ -980,6 +1007,11 @@ private InternalRelationshipBuilder CreateRelationshipBuilder(
                 value = ModelBuilder.ConventionDispatcher.OnForeignKeyAdded(value);
             }
 
+            if (value != null)
+            {
+                HasIndex(value.Metadata.Properties, configurationSource);
+            }
+
             return value;
         }
 
@@ -1372,23 +1404,27 @@ public RelationshipBuilderSnapshot(
                 InternalRelationshipBuilder relationship,
                 string navigationToPrincipalName,
                 string navigationToDependentName,
+                InternalIndexBuilder indexBuilder,
                 ConfigurationSource relationshipConfigurationSource)
             {
                 Relationship = relationship;
                 RelationshipConfigurationSource = relationshipConfigurationSource;
                 NavigationToPrincipalName = navigationToPrincipalName;
                 NavigationToDependentName = navigationToDependentName;
+                IndexBuilder = indexBuilder;
             }
 
             private InternalRelationshipBuilder Relationship { get; }
             private ConfigurationSource RelationshipConfigurationSource { get; }
             private string NavigationToPrincipalName { get; }
             private string NavigationToDependentName { get; }
+            private InternalIndexBuilder IndexBuilder { get; }
 
             public InternalRelationshipBuilder Attach()
                 => Relationship.Attach(
                     NavigationToPrincipalName,
                     NavigationToDependentName,
+                    IndexBuilder,
                     RelationshipConfigurationSource);
         }
     }

src/EntityFramework.Core/Metadata/Internal/InternalIndexBuilder.cs

@@ -17,26 +17,82 @@ public InternalIndexBuilder([NotNull] Index index, [NotNull] InternalModelBuilde
         {
         }
 
-        public virtual bool IsUnique(bool? isUnique, ConfigurationSource configurationSource)
+        public virtual bool IsUnique(bool unique, ConfigurationSource configurationSource)
+            => IsUnique(unique, configurationSource, runConventions: true);
+
+        public virtual bool IsUnique(bool unique, ConfigurationSource configurationSource, bool runConventions)
         {
-            if (configurationSource.CanSet(_isUniqueConfigurationSource, Metadata.IsUnique.HasValue)
-                || Metadata.IsUnique.Value == isUnique)
+            if (!CanSetUnique(unique, configurationSource))
             {
-                if (_isUniqueConfigurationSource == null
-                    && Metadata.IsUnique != null)
-                {
-                    _isUniqueConfigurationSource = ConfigurationSource.Explicit;
-                }
-                else
+                return false;
+            }
+
+            var foreignKeys = Metadata.DeclaringEntityType.FindForeignKeys(Metadata.Properties);
+            foreach (var foreignKey in foreignKeys)
+            {
+                var relationshipBuilder = foreignKey.Builder;
+                if (foreignKey.PrincipalToDependent != null
+                    && !Navigation.IsCompatible(
+                        foreignKey.PrincipalToDependent.Name,
+                        foreignKey.PrincipalEntityType,
+                        foreignKey.DeclaringEntityType,
+                        shouldBeCollection: !unique,
+                        shouldThrow: false))
                 {
-                    _isUniqueConfigurationSource = configurationSource.Max(_isUniqueConfigurationSource);
+                    relationshipBuilder.Navigation(null, /* pointsToPrincipal: */ false, configurationSource, runConventions);
                 }
+            }
+
+            var newIndexBuilder = Metadata.DeclaringEntityType.Builder.HasIndex(Metadata.Properties.Select(p => p.Name).ToList(), ConfigurationSource.Convention);
+
+            if (newIndexBuilder.Metadata != Metadata)
+            {
+                return newIndexBuilder.IsUnique(unique, configurationSource);
+            }
+
+            if (_isUniqueConfigurationSource == null
+                    && Metadata.IsUnique != null)
+            {
+                _isUniqueConfigurationSource = ConfigurationSource.Explicit;
+            }
+            else
+            {
+                _isUniqueConfigurationSource = configurationSource.Max(_isUniqueConfigurationSource);
+            }
+            Metadata.IsUnique = unique;
+            return true;
+        }
 
-                Metadata.IsUnique = isUnique;
+        public virtual bool CanSetUnique(bool unique, ConfigurationSource configurationSource)
+        {
+            if (((IIndex)Metadata).IsUnique == unique)
+            {
                 return true;
             }
 
-            return false;
+            if (!configurationSource.CanSet(_isUniqueConfigurationSource, Metadata.IsUnique.HasValue))
+            {
+                return false;
+            }
+
+            var foreignKeys = Metadata.DeclaringEntityType.FindForeignKeys(Metadata.Properties);
+            foreach (var foreignKey in foreignKeys)
+            {
+                var relationshipBuilder = foreignKey.Builder;
+                if (foreignKey.PrincipalToDependent != null
+                    && !relationshipBuilder.CanSetNavigation(null, /* pointsToPrincipal */ false, configurationSource)
+                    && !Navigation.IsCompatible(
+                        foreignKey.PrincipalToDependent.Name,
+                        foreignKey.PrincipalEntityType,
+                        foreignKey.DeclaringEntityType,
+                        shouldBeCollection: !unique,
+                        shouldThrow: false))
+                {
+                    return false;
+                }
+            }
+
+            return true;
         }
 
         public virtual InternalIndexBuilder Attach(ConfigurationSource configurationSource)
@@ -46,12 +102,14 @@ public virtual InternalIndexBuilder Attach(ConfigurationSource configurationSour
 
             newIndexBuilder.MergeAnnotationsFrom(this);
 
-            if (_isUniqueConfigurationSource.HasValue)
+            if (_isUniqueConfigurationSource.HasValue && Metadata.IsUnique.HasValue)
             {
-                newIndexBuilder.IsUnique(Metadata.IsUnique, _isUniqueConfigurationSource.Value);
+                newIndexBuilder.IsUnique(Metadata.IsUnique.Value, _isUniqueConfigurationSource.Value);
             }
 
             return newIndexBuilder;
         }
+
+        public ConfigurationSource? GetIsUniqueConfigurationSource() => _isUniqueConfigurationSource;
     }
 }