TestDbContext.cs

public class TestDbContext : DbContext
{
    public DbSet<Order> Orders => Set<Order>();

    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    {
        var connectionString = "Server=localhost;Port=3307;Database=Demo;Uid=root;Pwd=root";
        optionsBuilder.UseMySql(connectionString, ServerVersion.AutoDetect(connectionString));

        optionsBuilder.LogTo(Console.WriteLine);
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Order>().HasKey(x => x.OrderId);
    }
}

public class Order
{
    [Key]
    public int OrderId { get; set; }
    
    public DateTime Date { get; set; }
    public int CustomerId { get; set; }
}