DbUpdateConcurrencyException when deleting an entity

[ulrich-berkmueller]

When using the InterBaseSql.EntityFrameworkCore.InterBase Version 10.0.2 we are unable to delete an entity.
Removing an entity and calling context.SaveChanges() always throws an Microsoft.EntityFrameworkCore.DbUpdateConcurrencyException.

See unit test InterBaseSql.EntityFrameworkCore.InterBase.Tests.EndToEnd.Delete() as code snippet to reproduce. This test fails.

IB.NETDataProvider/NETProvider/Provider/src/InterBaseSql.EntityFrameworkCore.InterBase.Tests/EndToEnd/DeleteTests.cs

Lines 53 to 64 in 0015a71

	public void Delete()
	{
	using (var db = GetDbContext<DeleteContext>())
	{
	db.Database.ExecuteSqlRaw("create table test_delete (id int not null, name varchar(20), primary key (ID))");
	db.Database.ExecuteSqlRaw("insert into test_delete values (65, 'test')");
	db.Database.ExecuteSqlRaw("insert into test_delete values (66, 'test')");
	db.Database.ExecuteSqlRaw("insert into test_delete values (67, 'test')");
	var entity = new DeleteEntity() { Id = 66 };
	var entry = db.Attach(entity);
	entry.State = EntityState.Deleted;
	db.SaveChanges();

Calling SaveChanges() throws the exception within Microsoft.EntityFrameworkCore.Update.AffectedCountModificationCommandBatch::Consume(RelationalDataReader reader).
https://github.com/dotnet/efcore/blob/6119066c37b98f604a5c868d691da0405d53e1aa/src/EFCore.Relational/Update/AffectedCountModificationCommandBatch.cs#L121C33-L121C74

The reader inside has no rows, only the property reader.RecordsAffected == 1.

See ResultSetMapping == ResultSetMapping.LastInResultSet where EF tries to get a row which does not exist.
https://github.com/dotnet/efcore/blob/6119066c37b98f604a5c868d691da0405d53e1aa/src/EFCore.Relational/Update/AffectedCountModificationCommandBatch.cs#L62C1-L66C1

IBUpdateSqlGenerator.AppendDeleteOperation() sets the ResultSetMapping to ResultSetMapping.LastInResultSet.

IB.NETDataProvider/NETProvider/Provider/src/InterBaseSql.EntityFrameworkCore.InterBase/Update/Internal/IBUpdateSqlGenerator.cs

Lines 87 to 98 in 0015a71

	public override ResultSetMapping AppendDeleteOperation(StringBuilder commandStringBuilder, IReadOnlyModificationCommand command, int commandPosition, out bool requiresTransaction)
	{
	var name = command.TableName;
	var operations = command.ColumnModifications;
	var conditionOperations = operations.Where(o => o.IsCondition).ToList();
	var inputOperations = GenerateParameters(conditionOperations);
	AppendDeleteCommandHeader(commandStringBuilder, name, null);
	AppendWhereClause(commandStringBuilder, conditionOperations);
	commandStringBuilder.Append(SqlGenerationHelper.StatementTerminator).AppendLine();
	requiresTransaction = true;
	return ResultSetMapping.LastInResultSet;
	}

The InterBaseSql.EntityFrameworkCore.InterBase.Update.Internal::AppendUpdateOperation sets the ResultSetMapping to ResultSetMapping.NoResults.

IB.NETDataProvider/NETProvider/Provider/src/InterBaseSql.EntityFrameworkCore.InterBase/Update/Internal/IBUpdateSqlGenerator.cs

Lines 64 to 85 in 0015a71

	public override ResultSetMapping AppendUpdateOperation(StringBuilder commandStringBuilder, IReadOnlyModificationCommand command, int commandPosition, out bool requiresTransaction)
	{
	var name = command.TableName;
	var operations = command.ColumnModifications;
	var writeOperations = operations.Where(o => o.IsWrite).ToList();
	var readOperations = operations.Where(o => o.IsRead).ToList();
	var conditionOperations = operations.Where(o => o.IsCondition).ToList();
	var anyRead = readOperations.Any();
	AppendUpdateCommandHeader(commandStringBuilder, name, null, writeOperations);
	AppendWhereClause(commandStringBuilder, conditionOperations);
	commandStringBuilder.Append(SqlGenerationHelper.StatementTerminator).AppendLine();
	//if (anyRead)
	//{
	// var keyOperations = operations.Where(o => o.IsKey).ToList();
	// return AppendSelectAffectedCommand(commandStringBuilder, name, null, readOperations, keyOperations, commandPosition);
	//}
	// commandStringBuilder.Append(SqlGenerationHelper.StatementTerminator).AppendLine();
	requiresTransaction = true;
	return ResultSetMapping.NoResults;
	}

Just to doublecheck, I modified AppendDeleteOperation to return ResultSetMapping.NoResults.
=> UnitTest Delete() passes.
Doing the same im my project and Remove/Delete works as expected.

Problem: Changing this behaviour means there is no UpdateConcurrency check any more (which would be appreciated for AppendUpdateOperation as well).

UnitTest InterBaseSql.EntityFrameworkCore.InterBase.Tests.EndToEnd::ConcurrencyDelete => fail
UnitTest InterBaseSql.EntityFrameworkCore.InterBase.Tests.EndToEnd::Delete => pass

Could you please help us with this issue? Delete functionality is essential.

Thanks and with kind regards,