Getting pedning migrations with EF Core 6

[ErikEJ]

I am using this with EF Core 5, but get Obsolete warnings:
'TypeMappingConvention' is obsolete: 'Use IModelRuntimeInitializer.Initialize instead.'
'RelationalModelConvention' is obsolete: 'Use IModelRuntimeInitializer.Initialize instead.'

Not really sure how to proceed...

            var migrationsAssembly = context.GetService<IMigrationsAssembly>();
            var modelDiffer = context.GetService<IMigrationsModelDiffer>();
            var dependencies = context.GetService<ProviderConventionSetBuilderDependencies>();
            var relationalDependencies = context.GetService<RelationalConventionSetBuilderDependencies>();

            var hasDifferences = false;

            if (migrationsAssembly.ModelSnapshot != null)
            {
                var typeMappingConvention = new TypeMappingConvention(dependencies);
                typeMappingConvention.ProcessModelFinalizing(((IConventionModel)migrationsAssembly.ModelSnapshot.Model).Builder, null);

                var relationalModelConvention = new RelationalModelConvention(dependencies, relationalDependencies);
                var sourceModel = relationalModelConvention.ProcessModelFinalized(migrationsAssembly.ModelSnapshot.Model);

                hasDifferences = modelDiffer.HasDifferences(
                     ((IMutableModel)sourceModel).FinalizeModel().GetRelationalModel(),
                    context.Model.GetRelationalModel());
            }

            var pendingModelChanges = (!databaseExists || hasDifferences);

EF Core version: 6.0
Target framework: NET 5.0

[AndriySvyryd]

This is tracked at dotnet/EntityFramework.Docs#3030

var snapshotModel = migrationsAssembly.ModelSnapshot?.Model;

if (snapshotModel is IMutableModel mutableModel)
{
    snapshotModel = mutableModel.FinalizeModel();
}

if (snapshotModel != null)
{
    snapshotModel = context.GetService<IModelRuntimeInitializer>().Initialize(snapshotModel);

    hasDifferences = modelDiffer.HasDifferences(snapshotModel.GetRelationalModel(), context.Model.GetRelationalModel());
}

However in preview3 the last line should be:

    hasDifferences = modelDiffer.HasDifferences(snapshotModel.GetRelationalModel(), context.DesignModel.GetRelationalModel());

[ErikEJ]

Thanks, just had to change:

.Initialize(snapshotModel, null)

[ErikEJ]

@AndriySvyryd - did this not make it into 6.0 preview 3?

//TODO 6.0 preview 3!
 hasDifferences = modelDiffer.HasDifferences(snapshotModel.GetRelationalModel(), context.DesignModel.GetRelationalModel())

[AndriySvyryd]

@ErikEJ No and for preview4 we changed the API to

hasDifferences = context.GetService<IMigrationsModelDiffer>().HasDifferences(
    snapshotModel.GetRelationalModel(),
    context.GetService<IDesignTimeModel>().Model.GetRelationalModel());

[ErikEJ]

Hmmm.. not exactly intuitive! Thanks.

[AndriySvyryd]

That's by-design 😄. We think that very few users would actually need that and if it turns out to be false, then we'll introduce an even simpler sugar API where the code in #24448 (comment) is replaced by a single call.

[ErikEJ]

You are probably right, I am the only person in the world who cares!