Mixing sproc and non-sproc commands in the same batch may fail with a NullReferenceException

[maboivin]

File a bug

Deleting a child entity when the parent entity uses DeleteUsingStoredProcedure fails with a NullReferenceException. It happens only when the child entity is already loaded in the entity tracker prior to deleting the parent entity.

Include your code

Repro project can be found here: https://github.com/maboivin/EFCoreIssueDeleteUsingStoredProcedure

using (var context = new ReproDbContext())
{
    context.Database.Migrate();

    var parent = new Parent() { Name = "parent" };
    context.Add(parent);
    context.SaveChanges();

    var child = new Child() { ParentId = parent.ParentId, Name = "child" };
    context.Add(child);
    context.SaveChanges();

    context.Remove(parent);

    // Since the parent entity is configured to be deleted with a stored procedure, it fails with a NullReferenceException.
    context.SaveChanges();
}

Include stack traces

Unhandled exception. Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while saving the entity changes. See the inner exception for details.
 ---> System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.Consume(RelationalDataReader reader)
   --- End of inner exception stack trace ---
   at Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch.Consume(RelationalDataReader reader)
   at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.Execute(IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.SqlServer.Update.Internal.SqlServerModificationCommandBatch.Execute(IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.Execute(IEnumerable`1 commandBatches, IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.Storage.RelationalDatabase.SaveChanges(IList`1 entries)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(IList`1 entriesToSave)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(StateManager stateManager, Boolean acceptAllChangesOnSuccess)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.<>c.<SaveChanges>b__107_0(DbContext _, ValueTuple`2 t)
   at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(Boolean acceptAllChangesOnSuccess)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChanges(Boolean acceptAllChangesOnSuccess)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChanges()
   at Program.<Main>$(String[] args) in C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\Program.cs:line 18

Include verbose output

SQL query executed when deleting the parent entity record:

declare @p4 int
set @p4=1
exec sp_executesql N'SET NOCOUNT ON;
DELETE FROM [Child]
OUTPUT 1
WHERE [ChildId] = @p0;
EXEC @p1 = [DeleteParent] @p2;
',N'@p0 uniqueidentifier,@p1 int output,@p2 uniqueidentifier',@p0='99DD433E-F36B-1410-82A4-00F564887FD3',@p1=@p4 output,@p2='97DD433E-F36B-1410-82A4-00F564887FD3'
select @p4

Database contexts:

PM> Get-DbContext -verbose
Using project 'EFCoreIssueDeleteUsingStoredProcedure'.
Using startup project 'EFCoreIssueDeleteUsingStoredProcedure'.
Build started...
Build succeeded.
C:\Program Files\dotnet\dotnet.exe exec --depsfile C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\bin\Debug\net7.0\EFCoreIssueDeleteUsingStoredProcedure.deps.json --additionalprobingpath C:\Users\maboivin\.nuget\packages --runtimeconfig C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\bin\Debug\net7.0\EFCoreIssueDeleteUsingStoredProcedure.runtimeconfig.json C:\Users\maboivin\.nuget\packages\microsoft.entityframeworkcore.tools\7.0.0\tools\netcoreapp2.0\any\ef.dll dbcontext list --json --verbose --no-color --prefix-output --assembly C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\bin\Debug\net7.0\EFCoreIssueDeleteUsingStoredProcedure.dll --project C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure.csproj --startup-assembly C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\bin\Debug\net7.0\EFCoreIssueDeleteUsingStoredProcedure.dll --startup-project C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure.csproj --project-dir C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\ --language C# --configuration Debug --working-dir C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure --root-namespace EFCoreIssueDeleteUsingStoredProcedure --nullable
Using assembly 'EFCoreIssueDeleteUsingStoredProcedure'.
Using startup assembly 'EFCoreIssueDeleteUsingStoredProcedure'.
Using application base 'C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\bin\Debug\net7.0'.
Using working directory 'C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure'.
Using root namespace 'EFCoreIssueDeleteUsingStoredProcedure'.
Using project directory 'C:\Dev\GitHub\maboivin\EFCoreIssueDeleteUsingStoredProcedure\EFCoreIssueDeleteUsingStoredProcedure\'.
Remaining arguments: .
Finding DbContext classes...
Finding IDesignTimeDbContextFactory implementations...
Finding application service provider in assembly 'EFCoreIssueDeleteUsingStoredProcedure'...
Finding Microsoft.Extensions.Hosting service provider...
No static method 'CreateHostBuilder(string[])' was found on class 'Program'.
No application service provider was found.
Finding DbContext classes in the project...
Found DbContext 'ReproDbContext'.

ReproDbContext

Include provider and version information

EF Core version: 7.0.0
Database provider: Microsoft.EntityFrameworkCore.SqlServer 7.0.0
Target framework: .NET 7.0
Operating system: Windows 11 21H2 (Build 22000.1219)
IDE: Visual Studio 2022 17.4.0

[roji]

Thanks for the quality repro @maboivin! I've located the root cause and we'll likely patch 7.0 with the fix.

As a side note, you can replace this pattern in OnModelCreating:

var childBuilder = modelBuilder.Entity<Child>();
childBuilder.ToTable(nameof(Child));
childBuilder.HasKey(c => c.ChildId);
childBuilder.Property(c => c.ChildId).HasDefaultValueSql("NEWSEQUENTIALID()");
childBuilder.Property(c => c.Name).IsRequired();
childBuilder.HasOne(c => c.Parent).WithMany().HasForeignKey(c => c.ParentId);

... with the following, simpler one:

modelBuilder.Entity<Child>(b =>
{
    b.ToTable(nameof(Child));
    b.HasKey(c => c.ChildId);
    b.Property(c => c.ChildId).HasDefaultValueSql("NEWSEQUENTIALID()");
    b.Property(c => c.Name).IsRequired();
    b.HasOne(c => c.Parent).WithMany().HasForeignKey(c => c.ParentId);
});