Efcore: HasData() creating deletes and re-inserts for unchanged entities on subsequent migrations

[collinbarrett]

Issue

When I add a migration after filling out some HasData() on a modelBuilder.Entity<T>(), the migration works well. However, if I add another migration immediately following (without changing anything), the second migration deletes and re-inserts all of the seed data again.

Background

I asked a SO question yesterday, because I thought this was occurring because I was trying to seed from an external data source (.json files). However, I am seeing the same issue today with inline new-ing of seed data as the docs demonstrate.

Any given piece of seed data, if left unmodified in HasData(), should only appear in Up() of a single migration, correct? This is my first go at using EF Core migrations with seed data, so it is certainly possible that I have something configured incorrectly, or I missed something in how the feature is supposed to work.

This could very well be a Pomelo (provider) issue as well. I am not versed enough in EF Core to know how to discern which it might be.

Steps to reproduce

1. https://github.com/collinbarrett/FilterLists/commit/3786c835339e3663370b4225fc3fd05884d945cd Add the seed data. (I've seen suggested to use anonymous types to handle related data, but I did test with concrete types with the same result.)
2. https://github.com/collinbarrett/FilterLists/commit/f241d3e928701682fa0356f356671eb81fe05644 Then I add the first migration, which looks/works great.
3. Apply the migration by running the project which includes a call to MyDbContext.Database.Migrate();. Verified that seed data was successfully added to the db.
4. https://github.com/collinbarrett/FilterLists/commit/e227e333d7be4607e1bb9b612c44b24a5952f670 Then, I immediately try adding another migration with no changes to the code, which (presumably erroneously) deletes and re-inserts all of the data.

Alternate 1: uint -> int for Ids

Since I am somewhat swimming upstream using uints as Id types (blocked by https://github.com/aspnet/EntityFrameworkCore/issues/11597 / https://github.com/PomeloFoundation/Pomelo.EntityFrameworkCore.MySql/issues/601), I tried temporarily converting all of these to ints, with the same results.

1. https://github.com/collinbarrett/FilterLists/commit/4d7049d93b5a9aa3abdcff66eb89a3547b6887cf Convert types.
2. https://github.com/collinbarrett/FilterLists/commit/f4720da3b394ea6e05d4a539c1a3ffbb6f843214 Initial migration.
3. https://github.com/collinbarrett/FilterLists/commit/7f8bcfa9ded3ed89718e957ac47283efcc10ee1d Second migration (shows deletes and re-inserts).

Alternate 2: removing dynamic DateTime/Timestamp

Because I do have a couple DateTimes stored as Timestamps in this entity, I tried a variant removing the DateTime.Now calculation of these values thinking that the dynamic nature of these properties caused a re-generation of the seed data in the migration. (ref: https://github.com/aspnet/EntityFrameworkCore/issues/11969)

1. https://github.com/collinbarrett/FilterLists/commit/df5c1354f0440e0dde772369d9976f01876bc207 Remove DateTime.Now().
2. https://github.com/collinbarrett/FilterLists/commit/0f8fdd3474e8aae07abbdd9a31da617d65c6372d Initial migration.
3. https://github.com/collinbarrett/FilterLists/commit/cbfda72ea1ae824a052fffe57619bc8f1b9b0c4a Second migration (shows deletes and re-inserts).

Alternate 3: Alternate 1 + Alternate 2 (per)

1. Branched from Alternate 1 (pre-migrations)
2. https://github.com/collinbarrett/FilterLists/commit/fd33cbae49d73701b37d55a35899679bc0531a3b Remove DateTime.Now().
3. https://github.com/collinbarrett/FilterLists/commit/da5ae2bdf4cb17f2819a2646bad7c553c5ddafeb Initial migration.
4. https://github.com/collinbarrett/FilterLists/commit/062988110eb58b207a04bd840f7d5cfdf9f1dd75 Second migration (shows deletes and re-inserts).

Further technical details

EF Core version: 2.1.1
Database Provider: Pomelo.EntityFrameworkCore.MySql (2.1.1)
Operating system: Windows 10
IDE: Visual Studio 2017 15.8.2

[AndriySvyryd]

@collinbarrett Did you try using int Ids __and__ removing dynamic temporal values at the same time?

[collinbarrett]

@AndriySvyryd Good suggestion. Should've thought to try that. Will try that and provide any updates.

[collinbarrett]

@AndriySvyryd added "Alternate 3" to the OP. No dice.

[chrispickford]

Also experiencing this exact same issue, will endeavour to remove the duplicated InsertData and DeleteData statements from generated migrations until 2.2.0 drops.

[collinbarrett]

@chrispickford , which EF Provider are you using? Curious if it might be provider-specific or EF Core in general.

[chrispickford]

@collinbarrett Here's my context factory, I'm using SqlServer:

public class MyContextFactory : IDesignTimeDbContextFactory<MyContext>
{
  public MyContext CreateDbContext(string[] args)
  {
    var optionsBuilder = new DbContextOptionsBuilder<MyContext>();
    optionsBuilder.UseSqlServer(@"Server=.\SQLEXPRESS;Database=Test;Trusted_Connection=True;");

    return new MyContext(optionsBuilder.Options);
  }
}

In MyContext.cs, nothing fancy going on:

modelBuilder.Entity<Brand>(b =>
{
  b.HasData(SeedData.BrandData);
});

[collinbarrett]

Ok, I'm using Pomelo for MySQL, which is a bit off the main trail of SQL Server. So, I was thinking it could be a bug with that provider. So, thanks for verifying it occurs with SQL Server as well.

Is SeedData.BrandData just hard-coded new-ed data similar to what I was doing here?

[chrispickford]

Yes, just another static class for seed data, exactly like yours in fact.

I thought it might be due to using dynamic values, i.e. Guid.NewGuid(), I've since changed to using static hard-coded values and the issue still occurs.

internal static readonly Brand[] BrandData =
{
  new Brand {Id = 1, Name = "Brand X", Uuid = new Guid("e5f9762f-44ce-456e-b226-c8b2ae733f72")}
};

[kalebpol]

Yeah, i have this problem too. The migrations are created just fine when the primary key is an int, but with the entities that have a string as primary key the migrations delete and re-insert the data instead of updating it.

[AndriySvyryd]

"Alternate 2" now works correctly with the latest nightly build. Probably fixed by https://github.com/aspnet/EntityFrameworkCore/commit/c8e49968c7aa60a8e0f32da3ecedad5e7ffa3b59

[collinbarrett]

Thanks! Will test that out.

Issue is related to https://github.com/aspnet/EntityFrameworkCore/issues/13172