Attribute for configuring DeleteBehavior

src/EFCore/DeleteBehavior.cs → src/EFCore.Abstractions/DeleteBehavior.cs

@@ -10,12 +10,15 @@ namespace Microsoft.EntityFrameworkCore;
 /// <remarks>
 /// <para>
 /// Behaviors in the database are dependent on the database schema being created
-/// appropriately. Using Entity Framework Migrations or <see cref="DatabaseFacade.EnsureCreated" />
+/// appropriately. Using Entity Framework Migrations or
+/// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.infrastructure.databasefacade.ensurecreated">
+/// EnsureCreated()</see>
 /// will create the appropriate schema.
 /// </para>
 /// <para>
 /// Note that the in-memory behavior for entities that are currently tracked by
-/// the <see cref="DbContext" /> can be different from the behavior that happens in the database.
+/// the <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext">DbContext</see>
+/// can be different from the behavior that happens in the database.
 /// </para>
 /// <para>
 /// See <see href="https://aka.ms/efcore-docs-cascading">Cascade delete and deleting orphans in EF Core</see> for more information and
@@ -25,16 +28,20 @@ namespace Microsoft.EntityFrameworkCore;
 public enum DeleteBehavior
 {
  /// <summary>
- /// For entities being tracked by the <see cref="DbContext" />, the values of foreign key properties in
+ /// For entities being tracked by the <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext">
+ /// DbContext</see>, the values of foreign key properties in
  /// dependent entities are set to null when the related principal is deleted.
  /// This helps keep the graph of entities in a consistent state while they are being tracked, such that a
  /// fully consistent graph can then be written to the database. If a property cannot be set to null because
- /// it is not a nullable type, then an exception will be thrown when <see cref="DbContext.SaveChanges()" /> is called.
+ /// it is not a nullable type, then an exception will be thrown when
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext.savechanges?view=efcore-6.0#microsoft-entityframeworkcore-dbcontext-savechanges" >
+ /// SaveChanges()</see> is called.
  /// </summary>
  /// <remarks>
  /// <para>
  /// If the database has been created from the model using Entity Framework Migrations or the
- /// <see cref="DatabaseFacade.EnsureCreated" /> method, then the behavior in the database
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.infrastructure.databasefacade.ensurecreated">
+ /// EnsureCreated()</see> method, then the behavior in the database
  /// is to generate an error if a foreign key constraint is violated.
  /// </para>
  /// <para>
@@ -45,29 +52,35 @@ public enum DeleteBehavior
  ClientSetNull,
 
  /// <summary>
- /// For entities being tracked by the <see cref="DbContext" />, the values of foreign key properties in
- /// dependent entities are set to null when the related principal is deleted.
+ /// For entities being tracked by the <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext">
+ /// DbContext</see>, the values of foreign key properties in dependent entities are set to null when the related principal is deleted.
  /// This helps keep the graph of entities in a consistent state while they are being tracked, such that a
  /// fully consistent graph can then be written to the database. If a property cannot be set to null because
- /// it is not a nullable type, then an exception will be thrown when <see cref="DbContext.SaveChanges()" /> is called.
+ /// it is not a nullable type, then an exception will be thrown when
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext.savechanges?view=efcore-6.0#microsoft-entityframeworkcore-dbcontext-savechanges" >
+ /// SaveChanges()</see> is called.
  /// </summary>
  /// <remarks>
  /// If the database has been created from the model using Entity Framework Migrations or the
- /// <see cref="DatabaseFacade.EnsureCreated" /> method, then the behavior in the database
- /// is to generate an error if a foreign key constraint is violated.
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.infrastructure.databasefacade.ensurecreated">
+ /// EnsureCreated()</see> method, then the behavior in the database is to generate an error if a foreign key constraint is violated.
  /// </remarks>
  Restrict,
 
  /// <summary>
- /// For entities being tracked by the <see cref="DbContext" />, the values of foreign key properties in
+ /// For entities being tracked by the <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext">
+ /// DbContext</see>, the values of foreign key properties in
  /// dependent entities are set to null when the related principal is deleted.
  /// This helps keep the graph of entities in a consistent state while they are being tracked, such that a
  /// fully consistent graph can then be written to the database. If a property cannot be set to null because
- /// it is not a nullable type, then an exception will be thrown when <see cref="DbContext.SaveChanges()" /> is called.
+ /// it is not a nullable type, then an exception will be thrown when
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext.savechanges?view=efcore-6.0#microsoft-entityframeworkcore-dbcontext-savechanges" >
+ /// SaveChanges()</see> is called.
  /// </summary>
  /// <remarks>
  /// If the database has been created from the model using Entity Framework Migrations or the
- /// <see cref="DatabaseFacade.EnsureCreated" /> method, then the behavior in the database is
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.infrastructure.databasefacade.ensurecreated">
+ /// EnsureCreated()</see> method, then the behavior in the database is
  /// the same as is described above for tracked entities. Keep in mind that some databases cannot easily
  /// support this behavior, especially if there are cycles in relationships, in which case it may
  /// be better to use <see cref="ClientSetNull" /> which will allow EF to cascade null values
@@ -76,13 +89,15 @@ public enum DeleteBehavior
  SetNull,
 
  /// <summary>
- /// For entities being tracked by the <see cref="DbContext" />, dependent entities
+ /// For entities being tracked by the <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext">
+ /// DbContext</see>, dependent entities
  /// will be deleted when the related principal is deleted.
  /// </summary>
  /// <remarks>
  /// <para>
  /// If the database has been created from the model using Entity Framework Migrations or the
- /// <see cref="DatabaseFacade.EnsureCreated" /> method, then the behavior in the database is
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.infrastructure.databasefacade.ensurecreated">
+ /// EnsureCreated()</see> method, then the behavior in the database is
  /// the same as is described above for tracked entities. Keep in mind that some databases cannot easily
  /// support this behavior, especially if there are cycles in relationships, in which case it may
  /// be better to use <see cref="ClientCascade" /> which will allow EF to perform cascade deletes
@@ -96,27 +111,30 @@ public enum DeleteBehavior
  Cascade,
 
  /// <summary>
- /// For entities being tracked by the <see cref="DbContext" />, dependent entities
+ /// For entities being tracked by the <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext">
+ /// DbContext</see>, dependent entities
  /// will be deleted when the related principal is deleted.
  /// </summary>
  /// <remarks>
  /// If the database has been created from the model using Entity Framework Migrations or the
- /// <see cref="DatabaseFacade.EnsureCreated" /> method, then the behavior in the database
- /// is to generate an error if a foreign key constraint is violated.
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.infrastructure.databasefacade.ensurecreated">
+ /// EnsureCreated()</see> method, then the behavior in the database is to generate an error if a foreign key constraint is violated.
  /// </remarks>
  ClientCascade,
 
  /// <summary>
- /// For entities being tracked by the <see cref="DbContext" />, the values of foreign key properties in
- /// dependent entities are set to null when the related principal is deleted.
+ /// For entities being tracked by the <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext">
+ /// DbContext</see>, the values of foreign key properties in dependent entities are set to null when the related principal is deleted.
  /// This helps keep the graph of entities in a consistent state while they are being tracked, such that a
  /// fully consistent graph can then be written to the database. If a property cannot be set to null because
- /// it is not a nullable type, then an exception will be thrown when <see cref="DbContext.SaveChanges()" /> is called.
+ /// it is not a nullable type, then an exception will be thrown when
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext.savechanges?view=efcore-6.0#microsoft-entityframeworkcore-dbcontext-savechanges" >
+ /// SaveChanges()</see> is called.
  /// </summary>
  /// <remarks>
  /// If the database has been created from the model using Entity Framework Migrations or the
- /// <see cref="DatabaseFacade.EnsureCreated" /> method, then the behavior in the database
- /// is to generate an error if a foreign key constraint is violated.
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.infrastructure.databasefacade.ensurecreated">
+ /// EnsureCreated()</see> method, then the behavior in the database is to generate an error if a foreign key constraint is violated.
  /// </remarks>
  NoAction,
 
@@ -126,15 +144,15 @@ public enum DeleteBehavior
  /// </summary>
  /// <remarks>
  /// <para>
- /// For entities being tracked by the <see cref="DbContext" />, the values of foreign key properties in
- /// dependent entities are not changed when the related principal entity is deleted.
+ /// For entities being tracked by the <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.dbcontext">
+ /// DbContext</see>, the values of foreign key properties in dependent entities are not changed when the related principal entity is deleted.
  /// This can result in an inconsistent graph of entities where the values of foreign key properties do
  /// not match the relationships in the graph.
  /// </para>
  /// <para>
  /// If the database has been created from the model using Entity Framework Migrations or the
- /// <see cref="DatabaseFacade.EnsureCreated" /> method, then the behavior in the database
- /// is to generate an error if a foreign key constraint is violated.
+ /// <see href="https://docs.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.infrastructure.databasefacade.ensurecreated">
+ /// EnsureCreated()</see> method, then the behavior in the database is to generate an error if a foreign key constraint is violated.
  /// </para>
  /// </remarks>
  ClientNoAction

src/EFCore.Abstractions/DeleteBehaviorAttribute.cs

@@ -0,0 +1,29 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore;
+
+/// <summary>
+/// Configures the Property or Field to indicate how a delete operation is applied to dependent entities
+/// in a relationship when it is deleted or the relationship is severed.
+/// </summary>
+/// <remarks>
+/// See <see href="https://aka.ms/efcore-docs-modeling">Modeling entity types and relationships</see> for more information and examples.
+/// </remarks>
+[AttributeUsage(AttributeTargets.Property | AttributeTargets.Field)]
+public sealed class DeleteBehaviorAttribute : Attribute
+{
+ /// <summary>
+ /// Initializes a new instance of the <see cref="DeleteBehaviorAttribute" /> class.
+ /// </summary>
+ /// <param name="behavior">The DeleteBehavior value of entity</param>
+ public DeleteBehaviorAttribute(DeleteBehavior behavior)
+ {
+ Behavior = behavior;
+ }
+
+ /// <summary>
+ /// The DeleteBehavior value
+ /// </summary>
+ public DeleteBehavior Behavior { get; }
+}

src/EFCore/Metadata/Conventions/DeleteBehaviorAttributeConvention.cs

@@ -0,0 +1,46 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace Microsoft.EntityFrameworkCore.Metadata.Conventions;
+
+/// <summary>
+/// A convention that configures the DeleteBehavior based on the <see cref="DeleteBehaviorAttribute" /> applied on the property.
+/// </summary>
+/// <remarks>
+/// See <see href="https://aka.ms/efcore-docs-conventions">Model building conventions</see> for more information and examples.
+/// </remarks>
+public class DeleteBehaviorAttributeConvention : IForeignKeyAddedConvention
+{
+ /// <summary>
+ /// Creates a new instance of <see cref="UnicodeAttributeConvention" />.
+ /// </summary>
+ /// <param name="dependencies">Parameter object containing dependencies for this convention.</param>
+ public DeleteBehaviorAttributeConvention(ProviderConventionSetBuilderDependencies dependencies)
+ {
+ Dependencies = dependencies;
+ }
+
+ /// <summary>
+ /// Dependencies for this service.
+ /// </summary>
+ protected virtual ProviderConventionSetBuilderDependencies Dependencies { get; }
+
+ /// <summary>
+ /// Called after a foreign key is added to the entity type.
+ /// </summary>
+ /// <param name="foreignKeyBuilder">The builder for the foreign key.</param>
+ /// <param name="context">Additional information associated with convention execution.</param>
+ public virtual void ProcessForeignKeyAdded(IConventionForeignKeyBuilder foreignKeyBuilder, IConventionContext<IConventionForeignKeyBuilder> context)
+ {
+ var foreignKey = foreignKeyBuilder.Metadata;
+ var properties = foreignKey.Properties;
+ foreach (var property in properties)
+ {
+ var attribute = property?.PropertyInfo?.GetCustomAttribute<DeleteBehaviorAttribute>();
+ if (attribute != null)
+ {
+ foreignKey.SetDeleteBehavior(attribute.Behavior);
+ }
+ }
+ }
+}

src/EFCore/Metadata/Conventions/Infrastructure/ProviderConventionSetBuilder.cs

@@ -141,13 +141,15 @@ public virtual ConventionSet CreateConventionSet()
  conventionSet.KeyRemovedConventions.Add(keyDiscoveryConvention);
 
  var cascadeDeleteConvention = new CascadeDeleteConvention(Dependencies);
+ var deleteBehaviorAttributeConvention = new DeleteBehaviorAttributeConvention(Dependencies);
 
  conventionSet.ForeignKeyAddedConventions.Add(foreignKeyAttributeConvention);
  conventionSet.ForeignKeyAddedConventions.Add(foreignKeyPropertyDiscoveryConvention);
  conventionSet.ForeignKeyAddedConventions.Add(keyDiscoveryConvention);
  conventionSet.ForeignKeyAddedConventions.Add(valueGeneratorConvention);
  conventionSet.ForeignKeyAddedConventions.Add(cascadeDeleteConvention);
  conventionSet.ForeignKeyAddedConventions.Add(foreignKeyIndexConvention);
+ conventionSet.ForeignKeyAddedConventions.Add(deleteBehaviorAttributeConvention);
 
  conventionSet.ForeignKeyRemovedConventions.Add(baseTypeDiscoveryConvention);
  conventionSet.ForeignKeyRemovedConventions.Add(relationshipDiscoveryConvention);

src/EFCore/Properties/TypeForwards.cs

@@ -8,3 +8,4 @@
 [assembly: TypeForwardedTo(typeof(ObservableCollectionExtensions))]
 [assembly: TypeForwardedTo(typeof(ObservableCollectionListSource<>))]
 [assembly: TypeForwardedTo(typeof(SortableBindingList<>))]
+[assembly: TypeForwardedTo(typeof(DeleteBehavior))]

test/EFCore.Design.Tests/Migrations/ModelSnapshotSqlServerTest.cs

@@ -6083,6 +6083,7 @@ protected virtual ICollection<BuildReference> GetReferences()
  => new List<BuildReference>
  {
  BuildReference.ByName("Microsoft.EntityFrameworkCore"),
+ BuildReference.ByName("Microsoft.EntityFrameworkCore.Abstractions"),
  BuildReference.ByName("Microsoft.EntityFrameworkCore.Relational"),
  BuildReference.ByName("Microsoft.EntityFrameworkCore.SqlServer"),
  BuildReference.ByName("NetTopologySuite")

test/EFCore.Relational.Specification.Tests/Migrations/MigrationsTestBase.cs

@@ -2023,6 +2023,7 @@ protected IModel BuildModelFromSnapshotSource(string code)
 
  // Add standard EF references, a reference to the provider's assembly, and any extra references added by the provider's test suite
  build.References.Add(BuildReference.ByName("Microsoft.EntityFrameworkCore"));
+ build.References.Add(BuildReference.ByName("Microsoft.EntityFrameworkCore.Abstractions"));
  build.References.Add(BuildReference.ByName("Microsoft.EntityFrameworkCore.Relational"));
 
  var databaseProvider = Fixture.TestHelpers.CreateContextServices().GetRequiredService<IDatabaseProvider>();