EF Core 6.0 temporal tables - Support specifying precision for PeriodEnd and PeriodStart columns

[Mithras]

What problem are you trying to solve?

Right now it's not possible to specify precision for PeriodEnd and PeriodStart columns. We already have temporal tables in our DB and we happened to use datetime2(0) instead of just datetime2 for PeriodEnd and PeriodStart columns.

Describe the solution you'd like

builder.ToTable(tableBuilder => tableBuilder.IsTemporal(temporalTableBuilder =>
{
  temporalTableBuilder.HasPeriodStart("MyPeriodStart").HasPrecision(0); // <--- something like this
  temporalTableBuilder.HasPeriodEnd("MyPeriodEnd").HasPrecision(0); // <--- something like this
  temporalTableBuilder.UseHistoryTable("MyHistory");
}));

[ajcvickers]

Note for triage. While the model builder does allow configuration of the shadow properties with:

modelBuilder.Entity<Employee>().Property("MyPeriodStart").HasPrecision(0);

Or

modelBuilder.Entity<Employee>().Property("MyPeriodStart").HasColumnType("datetime2(0)");

The model validator requires that the type be exactly "datetime2":

const string expectedPeriodColumnName = "datetime2";
if (periodProperty.GetColumnType() != expectedPeriodColumnName)
{
    throw new InvalidOperationException(
        SqlServerStrings.TemporalPeriodPropertyMustBeMappedToDatetime2(
            temporalEntityType.DisplayName(), periodProperty.Name, expectedPeriodColumnName));
}