I am on an Intel chip Mac.

When I do dotnet run, I expected the table Player to be created, and the data to be seeded from ApplicationDbContext.cs. I see the table being created, but no data inserted.

My implementation is quite basic with an SQLite db, but not sure why it is not working?

Output:

Player.cs

namespace OneModel.Models
{
    public class Player
    {
        public int PlayerId { get; set; }
        public string PlayerName { get; set; }

        public Player()
        {
        }
    }
}

ApplicationDbContext.cs

using Microsoft.EntityFrameworkCore;
using OneModel.Models;

namespace OneModel.Data
{
    public class ApplicationDbContext : DbContext
    {
        public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options)
        {
            
        }
        public DbSet<Player> Players { get; set; }

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

            builder.Entity<Player>().HasData(
                new
                {
                    PlayerId = 1,
                    PlayerName = "Edgar",
                }
            );
        }
    }
}

Program.cs

using Microsoft.EntityFrameworkCore;
using OneModel.Data;

var builder = WebApplication.CreateBuilder(args);

var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlite(connectionString));

// Add services to the container.
builder.Services.AddControllersWithViews();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    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.UseStaticFiles();

app.UseRouting();

app.UseAuthorization();

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

using (var scope = app.Services.CreateScope()) {
var services = scope.ServiceProvider;
var context = services.GetRequiredService<ApplicationDbContext>();
context.Database.Migrate();
}

app.Run();

CodePudding user response：

The error is explained 2 lines above your arrow in your screenshot: 'PLAYERID INTEGER NOT NULL CONSTRAINT PK_PLAYERS PRIMARY KEY AUTOINCREMENT'

This means that the database is trying to set the ID but you are trying to inject it yourself. Remove the PlayerId=1 from your seed.

Also, add the [Key] attribute to the PlayerId field, I know that using {Id} is implicit and the same. But you might want to keep in control and use the key to make it more clear to yourself and others that this is the primary key.

CodePudding user response：

Anyway, I played around and was finally able to fix using these steps:

1. Delete the existing app.db.
2. Recreate a blank app.db file.
3. Re-migrate the Models using dotnet-ef migrations add CreateTables -o Data/Migrations
4. dotnet run to seed again, and should work now.

I am not sure why the problem occurred in the first place. Perhaps my original setup was trying to seed from ApplicationDbContext.cs before the migration in Program.cs.