Unable to add migrations for Identity in ASP.NET Core using Update-Database and Npgsql

[cirrusone]

Creating a new project and trying to add migrations gives me the following error. Any idea how to solve this?

PM> Add-Migration CreateIdentitySchema
Build started...
Build succeeded.
To undo this action, use Remove-Migration.
PM> Update-Database
Build started...
Build succeeded.
fail: Microsoft.EntityFrameworkCore.Database.Command[20102]
      Failed executing DbCommand (14ms) [Parameters=[], CommandType='Text', CommandTimeout='600']
      SELECT "MigrationId", "ProductVersion"
      FROM "__EFMigrationsHistory"
      ORDER BY "MigrationId";
Failed executing DbCommand (14ms) [Parameters=[], CommandType='Text', CommandTimeout='600']
SELECT "MigrationId", "ProductVersion"
FROM "__EFMigrationsHistory"
ORDER BY "MigrationId";
System.InvalidOperationException: An error was generated for warning 'Microsoft.EntityFrameworkCore.Migrations.PendingModelChangesWarning': The model for context 'ApplicationDbContext' has pending changes. Add a new migration before updating the database. This exception can be suppressed or logged by passing event ID 'RelationalEventId.PendingModelChangesWarning' to the 'ConfigureWarnings' method in 'DbContext.OnConfiguring' or 'AddDbContext'.
   at Microsoft.EntityFrameworkCore.Diagnostics.EventDefinition`1.Log[TLoggerCategory](IDiagnosticsLogger`1 logger, TParam arg)
   at Microsoft.EntityFrameworkCore.Diagnostics.RelationalLoggerExtensions.PendingModelChangesWarning(IDiagnosticsLogger`1 diagnostics, Type contextType)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
   at Npgsql.EntityFrameworkCore.PostgreSQL.Migrations.Internal.NpgsqlMigrator.Migrate(String targetMigration)
   at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateDatabase(String targetMigration, String connectionString, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabaseImpl(String targetMigration, String connectionString, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.<>c__DisplayClass0_0.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
An error was generated for warning 'Microsoft.EntityFrameworkCore.Migrations.PendingModelChangesWarning': The model for context 'ApplicationDbContext' has pending changes. Add a new migration before updating the database. This exception can be suppressed or logged by passing event ID 'RelationalEventId.PendingModelChangesWarning' to the 'ConfigureWarnings' method in 'DbContext.OnConfiguring' or 'AddDbContext'.

These are the steps I'm performing

1/ Create the database in PostgreSQL.
2/ Create new project in VS - ASP.NET Core Web App (Model-View-Controller)

3/ Changed the project details for only the following

WebApplication1.csproj: add nuget Npgsql.EntityFrameworkCore.PostgreSQL

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net9.0</TargetFramework>
    <Nullable>enable</Nullable>
    <ImplicitUsings>enable</ImplicitUsings>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore" Version="9.0.0-rc.2.24474.3" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="9.0.0-rc.2.24474.3" />
    <PackageReference Include="Microsoft.AspNetCore.Identity.UI" Version="9.0.0-rc.2.24474.3" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="9.0.0-rc.2.24474.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="9.0.0-rc.2.24474.1" />
    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="9.0.0-rc.2" />
  </ItemGroup>

</Project>

Update connection string - this is definitely correct as works with other projects.

{
  "ConnectionStrings": {
    "DefaultConnection": "Server=127.0.0.1;Port=5432;Database=db********************;User Id=**********;Password=**********;Timeout=60;CommandTimeout=600;Include Error Detail=true;"
  },
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*"
}

Change db context:

using Microsoft.AspNetCore.Identity;
using Microsoft.EntityFrameworkCore;
using WebApplication1.Data;

namespace WebApplication1;

public class Program
{
    public static void Main(string[] args)
    {
        var builder = WebApplication.CreateBuilder(args);

        // Add services to the container.
        var connectionString = builder.Configuration.GetConnectionString("DefaultConnection") ?? throw new InvalidOperationException("Connection string 'DefaultConnection' not found.");

        //builder.Services.AddDbContext<ApplicationDbContext>(options => options.UseSqlServer(connectionString));
        builder.Services.AddDbContext<ApplicationDbContext>(options => options.UseNpgsql(connectionString));

        builder.Services.AddDatabaseDeveloperPageExceptionFilter();

        builder.Services.AddDefaultIdentity<IdentityUser>(options => options.SignIn.RequireConfirmedAccount = true)
            .AddEntityFrameworkStores<ApplicationDbContext>();

        builder.Services.AddControllersWithViews();

        var app = builder.Build();

        // Configure the HTTP request pipeline.
        if (app.Environment.IsDevelopment())
        {
            app.UseMigrationsEndPoint();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
            // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseRouting();

        app.UseAuthorization();

        app.MapStaticAssets();
        app.MapControllerRoute(
            name: "default",
            pattern: "{controller=Home}/{action=Index}/{id?}")
            .WithStaticAssets();
        app.MapRazorPages()
           .WithStaticAssets();

        app.Run();
    }
}

Add OnModelCreating to seed database with default identity:

using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;

namespace WebApplication1.Data;

// Remove-Migration
// Add-Migration CreateIdentitySchema
// Update-Database

public class ApplicationDbContext : IdentityDbContext
{
    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options)
    {
    }

    protected override void OnModelCreating(ModelBuilder builder)
    {
        base.OnModelCreating(builder);

        // Seed Roles
        builder.Entity<IdentityRole>().HasData(new IdentityRole
        {
            Id = "Administrator",
            Name = "Administrator",
            NormalizedName = "ADMINISTRATOR",
            ConcurrencyStamp = Guid.NewGuid().ToString()
        });
        builder.Entity<IdentityRole>().HasData(new IdentityRole
        {
            Id = "Member",
            Name = "Member",
            NormalizedName = "MEMBER",
            ConcurrencyStamp = Guid.NewGuid().ToString()
        });
        builder.Entity<IdentityRole>().HasData(new IdentityRole
        {
            Id = "Trial",
            Name = "Trial",
            NormalizedName = "TRIAL",
            ConcurrencyStamp = Guid.NewGuid().ToString()
        });

        // Seed User1
        IdentityUser user1 = new IdentityUser()
        {
            Id = "user1",
            Email = "***@***.com",
            UserName = "***@***.com",
            NormalizedEmail = "***@***.COM",
            NormalizedUserName = "***@***.COM",
            EmailConfirmed = true,
            SecurityStamp = Guid.NewGuid().ToString(),
            LockoutEnabled = true
        };
        user1.PasswordHash = new PasswordHasher<IdentityUser>().HashPassword(user1, "***********************");
        builder.Entity<IdentityUser>().HasData(user1);

        // User1 roles
        builder.Entity<IdentityUserRole<string>>().HasData(new IdentityUserRole<string>
        {
            RoleId = "Administrator",
            UserId = user1.Id
        });

        // Additional tables outside identity

    }
}

Delete existing migrations

00000000000000_CreateIdentitySchema.cs
ApplicationDbContextModelSnapshot.cs

Run the following commands in Package Manager Console:

Remove-Migration
Add-Migration CreateIdentitySchema
Update-Database

Not sure if it's an issue but original project created the migration in path ..\Data\Migrations but Add-Migration adds it to parent project path ..\Migrations

[cirrusone]

These steps actually work on a net8.0 project with <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="8.0.10" /> so it looks like an issue specific to net9 preview.