Temporal table migration regression from EF Core 8 to 9

[Moerup]

Migration regression from EF Core 8 to 9

I'm in the process of upgrading an application from .NET 8 to 9.

But I'm running into problems when trying to run existing migrations that have been created with EF Core 8 and working for over a year now on multiple versions of EF Core (8.0.4 to 8.0.11)

I have a migration that throws exceptions and can't complete at all on v9.0.0, but if I revert to 8.0.11 it works fine.
It's a series of multiple pretty complex migrations and changes over time, so creating a small repro will take some time, so I hope that's not necessary. Let me know if it is or you need more information!

Include your code

I have Temporal tables enabled for a model: "TestObjective" like this:

public void Configure(EntityTypeBuilder<TestObjective> builder)
{
    builder.ToTable(nameof(MasterCatalogueDbContext.TestObjectives), schema: DatabaseConstants.TestCatalogueSchemaName);

    // Enable history
    builder.Metadata.SetIsTemporal(true);

   // Removed relations, property configurations and Includes for brevity.
}

At some point we renamed a relations table from "TestObjectivesProjectRoles" to "TestObjectivesOwners".
All this is auto generated with dotnet-ef migrations add
But the migration generated to alter the temporal columns:

migrationBuilder.AlterColumn<DateTime>(
    name: "PeriodStart",
    schema: "testCatalogue",
    table: "TestObjectivesOwners",
    type: "datetime2",
    nullable: false,
    oldClrType: typeof(DateTime),
    oldType: "datetime2")
    .Annotation("SqlServer:IsTemporal", true)
    .Annotation("SqlServer:TemporalHistoryTableName", "TestObjectivesOwnersHistory")
    .Annotation("SqlServer:TemporalHistoryTableSchema", "testCatalogue")
    .Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
    .Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart")
    .OldAnnotation("SqlServer:IsTemporal", true)
    .OldAnnotation("SqlServer:TemporalHistoryTableName", "TestObjectivesProjectRolesHistory")
    .OldAnnotation("SqlServer:TemporalHistoryTableSchema", "testCatalogue")
    .OldAnnotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
    .OldAnnotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

Results in this error:

2024-11-14T15:07:43 [15:07:43 INF] Applying migration '20240102112555_RenameTestCatalogueOwnerTables'.
2024-11-14T15:07:44 [15:07:44 ERR] Failed executing DbCommand (22ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
2024-11-14T15:07:44 DECLARE @var4 sysname;
2024-11-14T15:07:44 SELECT @var4 = [d].[name]
2024-11-14T15:07:44 FROM [sys].[default_constraints] [d]
2024-11-14T15:07:44 INNER JOIN [sys].[columns] [c] ON [d].[parent_column_id] = [c].[column_id] AND [d].[parent_object_id] = [c].[object_id]
2024-11-14T15:07:44 WHERE ([d].[parent_object_id] = OBJECT_ID(N'[testCatalogue].[TestObjectivesOwners]') AND [c].[name] = N'PeriodStart');
2024-11-14T15:07:44 IF @var4 IS NOT NULL EXEC(N'ALTER TABLE [testCatalogue].[TestObjectivesOwners] DROP CONSTRAINT [' + @var4 + '];');
2024-11-14T15:07:44 ALTER TABLE [testCatalogue].[TestObjectivesOwners] ALTER COLUMN [PeriodStart] datetime2 GENERATED ALWAYS AS ROW START HIDDEN NOT NULL;
2024-11-14T15:07:44 [15:07:44 ERR] Failed to migrate MasterCatalogue database!
2024-11-14T15:07:44 Microsoft.Data.SqlClient.SqlException (0x80131904): Period column 'PeriodStart' in a system-versioned temporal table cannot be altered.
2024-11-14T15:07:44    at Microsoft.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
2024-11-14T15:07:44    at Microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
2024-11-14T15:07:44    at Microsoft.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
2024-11-14T15:07:44    at Microsoft.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
2024-11-14T15:07:44    at Microsoft.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean isAsync, Int32 timeout, Boolean asyncWrite)
2024-11-14T15:07:44    at Microsoft.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry, String methodName)
2024-11-14T15:07:44    at Microsoft.Data.SqlClient.SqlCommand.ExecuteNonQuery()
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteNonQuery(RelationalCommandParameterObject parameterObject)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.Migrations.MigrationCommand.ExecuteNonQuery(IRelationalConnection connection, IReadOnlyDictionary`2 parameterValues)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.Execute(IReadOnlyList`1 migrationCommands, IRelationalConnection connection, MigrationExecutionState executionState, Boolean beginTransaction, Boolean commitTransaction, Nullable`1 isolationLevel)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.<>c.<ExecuteNonQuery>b__3_1(DbContext _, ValueTuple`6 s)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.ExecuteNonQuery(IReadOnlyList`1 migrationCommands, IRelationalConnection connection, MigrationExecutionState executionState, Boolean commitTransaction, Nullable`1 isolationLevel)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.MigrateImplementation(DbContext context, String targetMigration, MigrationExecutionState state, Boolean useTransaction)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.<>c.<Migrate>b__20_1(DbContext c, ValueTuple`4 s)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
2024-11-14T15:07:44    at Microsoft.EntityFrameworkCore.RelationalDatabaseFacadeExtensions.Migrate(DatabaseFacade databaseFacade)
2024-11-14T15:07:44    at RTDT.MasterCatalogue.Web.Program.MigrateAndSeed(WebApplication app) in C:\GitVestas\RTDT\src\Services\RTDT.MasterCatalogue\src\RTDT.MasterCatalogue.Web\Program.cs:line 171
2024-11-14T15:07:44 ClientConnectionId:2bd97670-656a-4168-b8b1-d65d6137ead2
2024-11-14T15:07:44 Error Number:13599,State:1,Class:16

Include provider and version information

EF Core version: 9.0.0
Database provider: Microsoft.EntityFrameworkCore.SqlServer
Target framework: .NET 9.0
Operating system: Windows & Linux (Local & CICD)
IDE: Visual Studio Enterprise 2022 17.12.0

[bhp15973]

I have the same problem.
In our CICD we are always recreating db, so we execute always all migrations. I have seen that the difference is near PeriodStart/PeriodEnd
GENERATED ALWAYS AS ROW START HIDDEN is added in EF Core 9.
Our error says: cannot create generated always column when system_time period is not defined.

[Moerup]

@roji I can see you have changed the title to only indicate that it's temporal table related, but the second issue in my post does not seem related at all to temporal tables, but rowversion and it's default value.

Maybe I'm wrong tho and they are both related to temporal, just wanted to make sure that part doesn't get overlooked.

[roji]

@Moerup I indeed missed the 2nd issue - but it would be better to have that as a separate issue, as it indeed seems unrelated.

[danroot]

I get same error as @bhp15973
The generated migration is:
ALTER TABLE [InsuranceQuotes] ADD [PeriodEnd] datetime2 GENERATED ALWAYS AS ROW END HIDDEN NOT NULL DEFAULT '9999-12-31T23:59:59.9999999';

Resulting in this error from SQL:
Cannot create generated always column when SYSTEM_TIME period is not defined.

As far as I can tell this is a standard migration of a non-temporal table to a temporal table. This migration works in efcore 8.

I believe the issue is the ADD COLUMN and PERIOD FOR SYSTEM_TIME need to all happen at the same time:

ALTER TABLE dbo.YourTable
ADD SysStartTime datetime2 GENERATED ALWAYS AS ROW START NOT NULL,
SysEndTime datetime2 GENERATED ALWAYS AS ROW END NOT NULL,
PERIOD FOR SYSTEM_TIME (SysStartTime, SysEndTime);

in EF8 "GENERATED ALWAYS" is not specified.

[danroot]

I have created a repo that presents a minimal reproduction of what I think is the same or similar issue as OP. @Moerup let me know if this is a different issue and I will create a new issue. This is a blocking issue for my team adopting EFCore 9, which we really want to do!

https://github.com/danroot/Spike.EFCore9TemporalTable

Steps to reproduce with this repo:

• be sure the connection string is correct in OnConfiguring. Note the database will be dropped in the test.
• run the test
• observe test fails with "Cannot create generated always column when SYSTEM_TIME period is not defined"

Steps to reproduce from scratch:

• Create a EF Core 8 db context
• Add an initial migration
• Update the tables to use temporal tables in OnModelCreating of the db context: modelBuilder.Entity().ToTable("Contacts", b => b.IsTemporal());
• Add a migration for the db context
• Update the Microsoft.EntityFrameworkCore.* nuget packages to to EF Core 9
• Run the migration by calling context.Database.Migrate or using dotnet ef database update

[WolfspiritM]

We're also having the exact same problem with a migration that converts a non temporal table into a temporal table.
"Cannot create generated always column when SYSTEM_TIME period is not defined"

As we apply migrations from code when developing, this causes issues if there is no database available yet.

The problem is that Aspire 9 is based on EFCore 9 so we can't upgrade Aspire until this is fixed but Aspire only supports the last version so until this is fixed we're using a version of Aspire that is out of support. So we hope this gets fixed soon.

[danroot]

@WolfspiritM You can use Aspire with EFCore 8. In our main solution, because of this regression, we have Aspire running an ASP.NET Core 9 project using EFCore 8. The main thing I think might not work is health checks against the ef context. If you want a containerized SQL in development:

var sql = builder.AddSqlServer("sql")
    .WithLifetime(ContainerLifetime.Persistent)
    .AddDatabase("SomeProjectDevDb");

var api = builder.AddProject<Projects.SomeProject_Api>("someproject-api")
    .WithReference(sql,"DefaultConnection") // <--- makes ConnectionStrings__DefaultConnection get injected into config of api project

If you don't want containerized SQL Server, just inject the connectionstring:

var sql = builder.AddConnectionString("DefaultConnection");
var api = builder.AddProject<Projects.SomeProject_Api>("someproject-api")
    .WithReference(sql,"DefaultConnection");

In the api, the implication is that instead of this:

builder.AddSqlServerDbContext<MyDbContext>("myConnection");

We just continue to do this, same as always:

builder.Services.AddDbContext<MyDbContext>();

Of course we do want to get to EFCore 9, but hopefully this makes it less of a block.

In our case, the impact is that we can't run integration tests under EFCore 9. We have tests that create a blank database by running migrations, create a snapshot, then test and rollback snapshot after each test. In this scenario, the migrations to create the database fail. We also have code to let developers get a 'fresh' dev database from scratch. Again, the migrations fail in EFCore9, but not 8.

A nuclear option that might work depending on the use of the migrations is to reset migrations.

[WolfspiritM]

@WolfspiritM You can use Aspire with EFCore 8.

Thanks. My main issue was that the Aspire components for sqlserver were using efcore 9 packages.
But thanks to discord I figured out that Aspire 9 can be used with net8 and uses Efcore 8 packages then.
I forgot that EfCore is part of the "framework" 😄

So I will give Aspire 9 with net8 a try now until this issue is resolved.

[rhahmed1122]

getting same issue on migrating EF Core 8 to 9.
It's a potential blocker for my team to migrate from efcore 8 to 9.

we have some temporal tables and after updating efcore from 8 to 9. we are unable to update database through migration and getting following error.

Cannot create generated always column when SYSTEM_TIME period is not defined.

[GordonBeeming]

I'm running into the same issue at the moment, also moving from 8 to 9. Similar error messages to others

Column 'SysStartTime' in table 'MyDatabase.MySchema.MyTable' cannot be specified as 'GENERATED ALWAYS' in ALTER COLUMN statement.

[maumar]

thanks @danroot for the great repros! It was very helpful and fix is on the way. Several people are hitting this so we will try to fit this into the next available patch release (likely 9.0.2)

In the meantime, here is the workaround. It's a bit of work and may not be realistic if affected migrations are large enough, but hopefully will unblock some folks.

For the affected migration code (that work on temporal tables or convert from regular to temporal) look for migrationBuilder.AlterColumn, and migrationBuilder.CreateColumn that contain these annotations (should be pretty much all of the operations):

.Annotation("SqlServer:IsTemporal", true)
.Annotation("SqlServer:TemporalHistoryTableName", "HistoryTable")
.Annotation("SqlServer:TemporalHistoryTableSchema", null)
.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

For AlterColumnOperation, remove all those annotations (as well as .OldAnnotations entries for those 5 values)

.OldAnnotation("SqlServer:IsTemporal", true)
.OldAnnotation("SqlServer:TemporalHistoryTableName", "CustomersHistory")
.OldAnnotation("SqlServer:TemporalHistoryTableSchema", null)
.OldAnnotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
.OldAnnotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

After removing those annotations, if there are no other changes in that operation (i.e. or of the "old" properties have the same value as the new ones) - remove the migrationBuilder.AlterColumn code entirely for that column.

For CreateColumn, also remove those 5 annotations, but additionally for the period start column add:

.Annotation("SqlServer:TemporalIsPeriodStartColumn", true)

and for period end column add:

.Annotation("SqlServer:TemporalIsPeriodEndColumn", true)

If the migration creates a temporal table right away (rather than converting regular table into temporal), you also need to fix annotations on the CreateTable columns:

this is how the operation should look like initially:

migrationBuilder.CreateTable(
	name: "Customers",
	columns: table => new
	{
		Id = table.Column<int>(type: "int", nullable: false)
			.Annotation("SqlServer:Identity", "1, 1")
			.Annotation("SqlServer:IsTemporal", true)
			.Annotation("SqlServer:TemporalHistoryTableName", "CustomersHistory")
			.Annotation("SqlServer:TemporalHistoryTableSchema", null)
			.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
			.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart"),
		Name = table.Column<string>(type: "nvarchar(max)", nullable: false)
			.Annotation("SqlServer:IsTemporal", true)
			.Annotation("SqlServer:TemporalHistoryTableName", "CustomersHistory")
			.Annotation("SqlServer:TemporalHistoryTableSchema", null)
			.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
			.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart"),
		PeriodEnd = table.Column<DateTime>(type: "datetime2", nullable: false)
			.Annotation("SqlServer:IsTemporal", true)
			.Annotation("SqlServer:TemporalHistoryTableName", "CustomersHistory")
			.Annotation("SqlServer:TemporalHistoryTableSchema", null)
			.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
			.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart"),
		PeriodStart = table.Column<DateTime>(type: "datetime2", nullable: false)
			.Annotation("SqlServer:IsTemporal", true)
			.Annotation("SqlServer:TemporalHistoryTableName", "CustomersHistory")
			.Annotation("SqlServer:TemporalHistoryTableSchema", null)
			.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
			.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart")
	},
	constraints: table =>
	{
		table.PrimaryKey("PK_Customers", x => x.Id);
	})
	.Annotation("SqlServer:IsTemporal", true)
	.Annotation("SqlServer:TemporalHistoryTableName", "CustomersHistory")
	.Annotation("SqlServer:TemporalHistoryTableSchema", null!)
	.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
	.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

this is what it should be changed to:

migrationBuilder.CreateTable(
	name: "Customers",
	columns: table => new
	{
		Id = table.Column<int>(type: "int", nullable: false)
			.Annotation("SqlServer:Identity", "1, 1"),
		
		Name = table.Column<string>(type: "nvarchar(max)", nullable: false),
		
		PeriodEnd = table.Column<DateTime>(type: "datetime2", nullable: false)
			.Annotation("SqlServer:TemporalIsPeriodEndColumn", true),
		
		PeriodStart = table.Column<DateTime>(type: "datetime2", nullable: false)
			.Annotation("SqlServer:TemporalIsPeriodStartColumn", true)
	},
	constraints: table =>
	{
		table.PrimaryKey("PK_Customers", x => x.Id);
	})
	.Annotation("SqlServer:IsTemporal", true)
	.Annotation("SqlServer:TemporalHistoryTableName", "CustomersHistory")
	.Annotation("SqlServer:TemporalHistoryTableSchema", null!)
	.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
	.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

do not remove annotations on the CreateTable operation itself, just on the columns

Also note that period start and end columns each have an annotation added just like migrationBuilder.CreateColumn mentioned before.

[maumar]

as an example, Up method from @danroot 's repro migration in the file 20241121163049_Temporal.cs should look like this:

        protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.AlterTable(
                name: "Persons")
                .Annotation("SqlServer:IsTemporal", true)
                .Annotation("SqlServer:TemporalHistoryTableName", "PersonsHistory")
                .Annotation("SqlServer:TemporalHistoryTableSchema", null)
                .Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
                .Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

            migrationBuilder.AlterTable(
                name: "Contacts")
                .Annotation("SqlServer:IsTemporal", true)
                .Annotation("SqlServer:TemporalHistoryTableName", "ContactsHistory")
                .Annotation("SqlServer:TemporalHistoryTableSchema", null)
                .Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
                .Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

            //migrationBuilder.AlterColumn<string>(
            //    name: "LastName",
            //    table: "Persons",
            //    type: "nvarchar(100)",
            //    maxLength: 100,
            //    nullable: false,
            //    oldClrType: typeof(string),
            //    oldType: "nvarchar(100)",
            //    oldMaxLength: 100)
            //    //.Annotation("SqlServer:IsTemporal", true)
            //    //.Annotation("SqlServer:TemporalHistoryTableName", "PersonsHistory")
            //    //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
            //    //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
            //    //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

            //migrationBuilder.AlterColumn<string>(
            //    name: "FirstName",
            //    table: "Persons",
            //    type: "nvarchar(100)",
            //    maxLength: 100,
            //    nullable: false,
            //    oldClrType: typeof(string),
            //    oldType: "nvarchar(100)",
            //    oldMaxLength: 100)
            //    //.Annotation("SqlServer:IsTemporal", true)
            //    //.Annotation("SqlServer:TemporalHistoryTableName", "PersonsHistory")
            //    //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
            //    //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
            //    //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

            //migrationBuilder.AlterColumn<int>(
            //    name: "Id",
            //    table: "Persons",
            //    type: "int",
            //    nullable: false,
            //    oldClrType: typeof(int),
            //    oldType: "int")
            //    .Annotation("SqlServer:Identity", "1, 1")
            //    //.Annotation("SqlServer:IsTemporal", true)
            //    //.Annotation("SqlServer:TemporalHistoryTableName", "PersonsHistory")
            //    //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
            //    //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
            //    //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart")
            //    .OldAnnotation("SqlServer:Identity", "1, 1");

            migrationBuilder.AddColumn<DateTime>(
                name: "PeriodEnd",
                table: "Persons",
                type: "datetime2",
                nullable: false,
                defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified))
                //.Annotation("SqlServer:IsTemporal", true)
                //.Annotation("SqlServer:TemporalHistoryTableName", "PersonsHistory")
                //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
                //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
                //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");
                .Annotation("SqlServer:TemporalIsPeriodEndColumn", true);

            migrationBuilder.AddColumn<DateTime>(
                name: "PeriodStart",
                table: "Persons",
                type: "datetime2",
                nullable: false,
                defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified))
                //.Annotation("SqlServer:IsTemporal", true)
                //.Annotation("SqlServer:TemporalHistoryTableName", "PersonsHistory")
                //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
                //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
                //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");
                .Annotation("SqlServer:TemporalIsPeriodStartColumn", true);

            //migrationBuilder.AlterColumn<string>(
            //    name: "Phone",
            //    table: "Contacts",
            //    type: "nvarchar(20)",
            //    maxLength: 20,
            //    nullable: false,
            //    oldClrType: typeof(string),
            //    oldType: "nvarchar(20)",
            //    oldMaxLength: 20)
            //    //.Annotation("SqlServer:IsTemporal", true)
            //    //.Annotation("SqlServer:TemporalHistoryTableName", "ContactsHistory")
            //    //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
            //    //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
            //    //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

            //migrationBuilder.AlterColumn<int>(
            //    name: "PersonId",
            //    table: "Contacts",
            //    type: "int",
            //    nullable: true,
            //    oldClrType: typeof(int),
            //    oldType: "int",
            //    oldNullable: true)
            //    //.Annotation("SqlServer:IsTemporal", true)
            //    //.Annotation("SqlServer:TemporalHistoryTableName", "ContactsHistory")
            //    //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
            //    //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
            //    //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

            //migrationBuilder.AlterColumn<string>(
            //    name: "Name",
            //    table: "Contacts",
            //    type: "nvarchar(100)",
            //    maxLength: 100,
            //    nullable: false,
            //    oldClrType: typeof(string),
            //    oldType: "nvarchar(100)",
            //    oldMaxLength: 100)
            //    //.Annotation("SqlServer:IsTemporal", true)
            //    //.Annotation("SqlServer:TemporalHistoryTableName", "ContactsHistory")
            //    //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
            //    //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
            //    //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

            //migrationBuilder.AlterColumn<string>(
            //    name: "Email",
            //    table: "Contacts",
            //    type: "nvarchar(100)",
            //    maxLength: 100,
            //    nullable: false,
            //    oldClrType: typeof(string),
            //    oldType: "nvarchar(100)",
            //    oldMaxLength: 100)
            //    //.Annotation("SqlServer:IsTemporal", true)
            //    //.Annotation("SqlServer:TemporalHistoryTableName", "ContactsHistory")
            //    //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
            //    //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
            //    //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");

            //migrationBuilder.AlterColumn<int>(
            //    name: "Id",
            //    table: "Contacts",
            //    type: "int",
            //    nullable: false,
            //    oldClrType: typeof(int),
            //    oldType: "int")
            //    .Annotation("SqlServer:Identity", "1, 1")
            //    //.Annotation("SqlServer:IsTemporal", true)
            //    //.Annotation("SqlServer:TemporalHistoryTableName", "ContactsHistory")
            //    //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
            //    //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
            //    //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart")
            //    .OldAnnotation("SqlServer:Identity", "1, 1");

            migrationBuilder.AddColumn<DateTime>(
                name: "PeriodEnd",
                table: "Contacts",
                type: "datetime2",
                nullable: false,
                defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified))
                //.Annotation("SqlServer:IsTemporal", true)
                //.Annotation("SqlServer:TemporalHistoryTableName", "ContactsHistory")
                //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
                //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
                //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");
                .Annotation("SqlServer:TemporalIsPeriodEndColumn", true);

            migrationBuilder.AddColumn<DateTime>(
                name: "PeriodStart",
                table: "Contacts",
                type: "datetime2",
                nullable: false,
                defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified))
                //.Annotation("SqlServer:IsTemporal", true)
                //.Annotation("SqlServer:TemporalHistoryTableName", "ContactsHistory")
                //.Annotation("SqlServer:TemporalHistoryTableSchema", null)
                //.Annotation("SqlServer:TemporalPeriodEndColumnName", "PeriodEnd")
                //.Annotation("SqlServer:TemporalPeriodStartColumnName", "PeriodStart");
                .Annotation("SqlServer:TemporalIsPeriodEndColumn", true);
        }

[maumar]

reopening for potential patch

[maumar]

fixed for 9.0.2, closing