using Microsoft.EntityFrameworkCore;
public sealed class LabDb : DbContext
{
    public LabDb(DbContextOptions<LabDb> options) : base(options) { }
    public DbSet<Item> Items => Set<Item>();
    public string CustomNote { get; set; } = "";
}
public sealed class Item
{
    public int Id { get; set; }
    public string Name { get; set; } = "";
}