Deleting an entity not possible (DbUpdateConcurrencyException)

[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,

[ulrich-berkmueller]

Hi!

I have a question regarding the current state of the provider. While working with the EF Core InterBase provider, it appears that the implementation is primarily focused on read operations. Write operations — especially DELETE — still do not seem to work, and I also couldn’t find any tests covering this functionality.

I’m wondering whether this read‑only focus is intentional, or if full write support (including DELETE) is planned for future releases. Any clarification on whether this functionality is expected to be implemented or if the current scope is final would be greatly appreciated.

In case you like to have a look at it, we have a minimal test project for this.