BookStore_NET5/BookStore/AssemblyInfo.cs

using Microsoft.EntityFrameworkCore;
using System.Configuration;
using System.Windows;

[assembly: ThemeInfo(ResourceDictionaryLocation.None,
    ResourceDictionaryLocation.SourceAssembly)]

public class Book
{
    public int Id { get; set; }
    public string Name { get; set; }
    public decimal Price { get; set; }
    public string Category { get; set; }
    public string Author { get; set; }
}

public class BookStoreContext : DbContext
{
    public DbSet<Book> Books { get; set; }
    public BookStoreContext() { }
    protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
    { optionsBuilder.UseSqlServer(ConfigurationManager.ConnectionStrings["BookStore"].ConnectionString); }
}