Entity Framework Core - DbContext

1public class ApplicationDbContext : DbContext
2{
3    public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options)
4        : base(options) { }
5 
6    public DbSet<User> Users => Set<User>();
7    public DbSet<Order> Orders => Set<Order>();
8    public DbSet<Product> Products => Set<Product>();
9 
10    protected override void OnModelCreating(ModelBuilder modelBuilder)
11    {
12        modelBuilder.Entity<User>(entity =>
13        {
14            entity.HasKey(e => e.Id);
15            entity.Property(e => e.Email).IsRequired().HasMaxLength(256);
16            entity.HasIndex(e => e.Email).IsUnique();
17        });
18 
19        modelBuilder.Entity<Order>(entity =>
20        {
21            entity.HasOne(o => o.User)
22                .WithMany(u => u.Orders)
23                .HasForeignKey(o => o.UserId)
24                .OnDelete(DeleteBehavior.Cascade);
25        });
26    }
27}