Simplify configuration for temporal tables with owned types

[ajcvickers]

Ideally, of the owning entity type is configured as temporal, then owned entities mapped to the same table should not need additional configuration to make use of the temporal table, with the same PeriodStart and PeriodEnd columns.

For example, this configuration should be sufficient:

modelBuilder
    .Entity<Employee>()
    .ToTable("Employees", tableBuilder => tableBuilder.IsTemporal())
    .OwnsOne(employee => employee.Info);

But throws:

Entity type 'EmployeeInfo' should be marked as temporal because it shares table mapping with another entity that has been marked as temporal. Alternatively, other entity types that share the same table must be non-temporal.

Attempting to fix this:

modelBuilder
    .Entity<Employee>()
    .ToTable("Employees", tableBuilder => tableBuilder.IsTemporal())
    .OwnsOne(employee => employee.Info)
    .ToTable("Employees", tableBuilder => tableBuilder.IsTemporal());

Results in:

When multiple temporal entities are mapped to the same table, their period start properties must map to the same column. Issue happens for entity type 'EmployeeInfo' with period property 'PeriodStart' which is mapped to column 'EmployeeInfo_PeriodStart'. Ex
pected period column name is 'PeriodStart'.

Attempting the set the column name explicit on one or other type doesn't help. So the simplest config that I can come up with that works is:

modelBuilder
    .Entity<Employee>()
    .ToTable(
        "Employees",
        tableBuilder =>
        {
            tableBuilder.IsTemporal();
            tableBuilder.Property<DateTime>("PeriodStart").HasColumnName("PeriodStart");
            tableBuilder.Property<DateTime>("PeriodEnd").HasColumnName("PeriodEnd");
        })
    .OwnsOne(
        employee => employee.Info,
        ownedBuilder => ownedBuilder.ToTable(
            "Employees",
            tableBuilder =>
            {
                tableBuilder.IsTemporal();
                tableBuilder.Property<DateTime>("PeriodStart").HasColumnName("PeriodStart");
                tableBuilder.Property<DateTime>("PeriodEnd").HasColumnName("PeriodEnd");
            }));

[parvic1]

Any idea if this is being considered on coming releases?

[parvic1]

this worked for me:
builder.ToTable($"{nameof(SampleTestException)}s", t =>
{
t.IsTemporal(t1 =>
{
t1.UseHistoryTable($"{nameof(SampleTestException)}s_Audit");
t1.HasPeriodStart("ValidFrom");
t1.HasPeriodEnd("ValidTo");
});
t.Property("ValidFrom").HasColumnName("ValidFrom");
t.Property("ValidTo").HasColumnName("ValidTo");
}).HasKey(x => x.Id);

    builder.OwnsOne(p => p.Fraction1, ownedBilder =>
    {
        ownedBilder.Property(pp => pp.Name).HasMaxLength(50).IsUnicode(false);
        ownedBilder.Property(pp => pp.Value).HasColumnType("real");
        ownedBilder.Property(pp => pp.MinRangeValue).HasColumnType("real");
        ownedBilder.Property(pp => pp.MaxRangeValue).HasColumnType("real");

        ownedBilder.ToTable($"{nameof(SampleTestException)}s", tbuilder =>
        {
            tbuilder.IsTemporal(t1 =>
            {
                t1.UseHistoryTable($"{nameof(SampleTestException)}s_Audit");
                t1.HasPeriodStart("ValidFrom");
                t1.HasPeriodEnd("ValidTo");
            });
            tbuilder.Property<DateTime>("ValidFrom").HasColumnName("ValidFrom");
            tbuilder.Property<DateTime>("ValidTo").HasColumnName("ValidTo");
        });
    }
    );

[davidhenley]

Thanks. Mine was a little more complicated and since TemporalTableBuilder doesn't have HasColumnType I had to explicitly set the column to datetime2 on the main entity.

These are all things that could be simplified.

[PhilippeWaeber]

Having encountered this issue, I've use @ajcvickers approach, explained in the initial post and made a generic, reusable method:

private static void ConfigureOwnedNavigationProperty<TModel, TDependent>(OwnedNavigationBuilder<TModel, TDependent> ownedNavigationBuilder)
    where TModel : class
    where TDependent : class
{
    ownedNavigationBuilder.ToTable($"{typeof(TModel).Name}s",
                                   tableBuilder =>
                                   {
                                       tableBuilder.IsTemporal();

                                       tableBuilder.Property<DateTime>(PeriodStart).HasColumnName(PeriodStart);
                                       tableBuilder.Property<DateTime>(PeriodEnd).HasColumnName(PeriodEnd);
                                   });
}

IMO it makes it easier to use and reuse with e.g. this localized description

builder.OwnsOne(product => product.Description, ConfigureOwnedNavigationProperty);

The entity itself, must also be registered as temporal with the same period start/stop columns:

private static void ConfigureBase<TModel>(EntityTypeBuilder<TModel> builder)
    where TModel : BaseModel
{
    builder.HasKey(model => model.Id);

    builder.ToTable($"{typeof(TModel).Name}s",
                    tableBuilder =>
                    {
                        tableBuilder.IsTemporal();

                        tableBuilder.Property<DateTime>(PeriodStart).HasColumnName(PeriodStart);
                        tableBuilder.Property<DateTime>(PeriodEnd).HasColumnName(PeriodEnd);
                    });

    builder.Property(model => model.Id)
           .ValueGeneratedOnAdd();
}