2415/BookStore_/BookStoreContext.cs

using Microsoft.EntityFrameworkCore;
using System.Configuration;

namespace BookStore_
{
    class BookStoreContext : DbContext
    {
        public DbSet<Book> Books { get; set; }
        public BookStoreContext()
        {

        }
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.UseSqlServer(ConfigurationManager.ConnectionStrings["BookStore"].ConnectionString);
        }
    }
}