EF 4.3.1 Migrations Seeding not working as expecte

I am using EF 4.3.1 migrations and I have the Configuration class in which I have the following code:

internal sealed class Configuration : DbMigrationsConfiguration<DbContext>
{
    public Configuration()
    {
        AutomaticMigrationsEnabled = false;
    }

    protected override void Seed(PayByPhoneDbContext context)
    {
        context.Roles.AddOrUpdate(r => r.Name, new Role { Name = "A" }, new Role { Name = "B" });
        context.Administrators.AddOrUpdate(a => a.Email, new Administrator { Email = "a@a.com" Name = "A", Role = context.Roles.Local.SingleOrDefault(role => role.Name == "A") });
    }
}

Now when I run the migrate command (part of MSBuild script) when the DB does not exist, tables are created and the seeding takes place as expected. But when I run the migrate command on an existing database without any migrations and all data is already seeded (when update needs to occur instead of insert) I get an error on running the migrate command:

No pending explicit migrations.

Running Seed method.

System.Data.Entity.Infrastructure.DbUpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.Data.UpdateException: An error occurred while updating the entries. See the inner exception for details. ---> System.Data.SqlClient.SqlException: The UPDATE statement conflicted with the FOREIGN KEY constraint "FK_Administrators_Roles_RoleId". The conflict occurred in database "xxxDB", table "dbo.Roles", column 'Id'.

The statement has been terminated.

Stacktrace:

at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)
   at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning()
   at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
   at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)
   at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)
   at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)
   at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(DbAsyncResult result, String methodName, Boolean sendToPipe)
   at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()
   at System.Data.Mapping.Update.Internal.DynamicUpdateCommand.Execute(UpdateTranslator translator, EntityConnection connection, Dictionary`2 identifierValues, List`1 generatedValues)
   at System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager, IEntityAdapter adapter)
   --- End of inner exception stack trace ---
   at System.Data.Mapping.Update.Internal.UpdateTranslator.Update(IEntityStateManager stateManager, IEntityAdapter adapter)
   at System.Data.EntityClient.EntityAdapter.Update(IEntityStateManager entityCache)
   at System.Data.Objects.ObjectContext.SaveChanges(SaveOptions options)
   at System.Data.Entity.Internal.InternalContext.SaveChanges()
   --- End of inner exception stack trace ---
   at System.Data.Entity.Internal.InternalContext.SaveChanges()
   at System.Data.Entity.Internal.LazyInternalContext.SaveChanges()
   at System.Data.Entity.DbContext.SaveChanges()
   at System.Data.Entity.Migrations.DbMigrator.SeedDatabase()
   at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.SeedDatabase()
   at System.Data.Entity.Migrations.DbMigrator.Upgrade(IEnumerable`1 pendingMigrations, String targetMigrationId, String lastMigrationId)
   at System.Data.Entity.Migrations.Infrastructure.MigratorLoggingDecorator.Upgrade(IEnumerable`1 pendingMigrations, String targetMigrationId, String lastMigrationId)
   at System.Data.Entity.Migrations.DbMigrator.Update(String targetMigration)
   at System.Data.Entity.Migrations.Infrastructure.MigratorBase.Update(String targetMigration)
   at System.Data.Entity.Migrations.Design.ToolingFacade.UpdateRunner.RunCore()
   at System.Data.Entity.Migrations.Design.ToolingFacade.BaseRunner.Run()

Running SQL Server profiler I found the error occurred when executing:

exec sp_executesql N'update [dbo].[Administrators]
set [RoleId] = @0
where ([Id] = @1)
',N'@0 int,@1 bigint',@0=0,@1=1

What is the right way to seed data with foreign keys in the Seed method?

AddOrUpdate will reset columns which you don't specify to null (or zero in the case of an int).

My understanding was that this behavior (which is awful by the way) wouldn't apply to columns that it recognized as keys or as auto-increment, but apparently it is in your case.

My advice would be to do a check to make sure the role doesn't exist in the database and then do a standard add() if it doesn't.

I do this for all my seed data because you never know when you may provide an interface later for updating data you seeded, and you don't want the Seed() method to overwrite your changes in those circumstances.

Also keep in mind that if you ever choose to use the MigrateDatabaseToLatestVersion database initializer then Seed() will fire each time your app restarts (dll deployment, web.config update, etc).

It's best to code defensively in the Seed() method.

Update: Julie Lerman has a good blog post about this behavior.