Allow temporal period properties to be mapped to CLR properties

[roji]

Fixes #26463

Summary

Temporal period properties (PeriodStart/PeriodEnd) were previously required to be shadow properties. This PR removes that restriction, allowing them to be mapped to CLR properties on the entity type.

Changes

Product code

• Removed shadow-property validation in SqlServerModelValidator — the IsShadowProperty() check on period properties is no longer enforced.
• Added lambda-based HasPeriodStart/HasPeriodEnd overloads on TemporalTableBuilder<TEntity> and OwnedNavigationTemporalTableBuilder<TOwner, TDependentEntity> for strongly-typed configuration:

  entity.ToTable(tb => tb.IsTemporal(ttb =>
  {
      ttb.HasPeriodStart(e => e.PeriodStart);
      ttb.HasPeriodEnd(e => e.PeriodEnd);
  }));

Scaffolding

No change — period columns are still excluded from the scaffolding column query and generated as shadow properties by default.

Why it just works

• SqlServerTemporalConvention already discovers existing CLR properties via entityTypeBuilder.Property(typeof(DateTime), periodPropertyName).
• Period properties are configured with ValueGenerated.OnAddOrUpdate, which sets BeforeSaveBehavior to Ignore — so they're automatically excluded from INSERT/UPDATE even as CLR properties.

Tests

• Updated validator test to expect success for CLR period properties
• Added model building tests (string-based and lambda-based CLR period configuration)
• Updated scaffolding round-trip test (now succeeds instead of throwing)
• Added E2E functional tests exercising CLR period properties with temporal queries

[Copilot]

Pull request overview

Removes the restriction that SQL Server temporal period properties must be shadow properties, allowing them to be mapped to CLR properties, and adds strongly-typed (lambda) configuration APIs for temporal period properties.

Changes:

• Removed temporal period “shadow-only” validation from SqlServerModelValidator.
• Added lambda-based HasPeriodStart/HasPeriodEnd overloads for temporal table builders.
• Updated/added tests across validator, model building, scaffolding, and functional temporal query scenarios to cover CLR period properties.

Reviewed changes

Copilot reviewed 9 out of 10 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
test/EFCore.SqlServer.Tests/Infrastructure/SqlServerModelValidatorTest.cs	Updates validator test to accept CLR-mapped period properties.
test/EFCore.SqlServer.FunctionalTests/Query/TemporalTableSqlServerTest.cs	Adds functional coverage for CLR period properties (including temporal queries).
test/EFCore.SqlServer.FunctionalTests/ModelBuilding/SqlServerModelBuilderTestBase.cs	Adds model-building tests and test-builder support for lambda-based period configuration.
test/EFCore.Design.Tests/Scaffolding/Internal/CSharpDbContextGeneratorTest.cs	Updates scaffolding test to validate temporal metadata without expecting a validator exception.
src/EFCore.SqlServer/Metadata/Builders/TemporalTableBuilder`.cs	Adds lambda overloads for period start/end configuration on generic temporal builder.
src/EFCore.SqlServer/Metadata/Builders/OwnedNavigationTemporalTableBuilder``.cs	Adds lambda overloads for period start/end configuration on generic owned-navigation temporal builder.
src/EFCore.SqlServer/Infrastructure/Internal/SqlServerModelValidator.cs	Removes the check enforcing period properties to be shadow properties.
src/EFCore.SqlServer/Design/Internal/SqlServerAnnotationCodeGenerator.cs	Updates comment to reflect rev-eng behavior (period properties remain shadow by default).

Files not reviewed (1)

• src/EFCore.SqlServer/Properties/SqlServerStrings.Designer.cs: Language not supported

[Copilot]

Pull request overview

Copilot reviewed 10 out of 11 changed files in this pull request and generated 1 comment.

Files not reviewed (1)

• src/EFCore.SqlServer/Properties/SqlServerStrings.Designer.cs: Language not supported

[github-actions]

API review baseline changes for src/EFCore.SqlServer/EFCore.SqlServer.baseline.json

Show diff

The diff below was generated by ApiChief between the base and the PR.

  class Microsoft.EntityFrameworkCore.Metadata.Builders.OwnedNavigationTemporalTableBuilder<TOwnerEntity, TDependentEntity> : Microsoft.EntityFrameworkCore.Metadata.Builders.OwnedNavigationTemporalTableBuilder where TOwnerEntity : class where TDependentEntity : class
+ virtual OwnedNavigationTemporalPeriodPropertyBuilder OwnedNavigationTemporalTableBuilder<TOwnerEntity, TDependentEntity>.HasPeriodEnd(Expression<Func<TDependentEntity, DateTime>> propertyExpression);
+ virtual OwnedNavigationTemporalPeriodPropertyBuilder OwnedNavigationTemporalTableBuilder<TOwnerEntity, TDependentEntity>.HasPeriodStart(Expression<Func<TDependentEntity, DateTime>> propertyExpression);

  class Microsoft.EntityFrameworkCore.Metadata.Builders.TemporalTableBuilder<TEntity> : Microsoft.EntityFrameworkCore.Metadata.Builders.TemporalTableBuilder where TEntity : class
+ virtual TemporalPeriodPropertyBuilder TemporalTableBuilder<TEntity>.HasPeriodEnd(Expression<Func<TEntity, DateTime>> propertyExpression);
+ virtual TemporalPeriodPropertyBuilder TemporalTableBuilder<TEntity>.HasPeriodStart(Expression<Func<TEntity, DateTime>> propertyExpression);