Entity Framework实例

1、数据定义

Book表

using System;
using System.Data.Objects;
using System.Data.Objects.DataClasses;
using System.Data.EntityClient;
using System.ComponentModel;
using System.Data.Entity;
using System.ComponentModel.DataAnnotations;

namespace EFTest.Models.Part2
{
    [Table("Book")]
    public class Book
    {
        [Key]
        public int BookId { get; set;}
        public string BookName { get; set; }
        public int CatalogId { get; set; }

        public virtual Catalog catalog { get; set; }
    }

}

Catalog表

using System;
using System.Data.Objects;
using System.Data.Objects.DataClasses;
using System.Data.EntityClient;
using System.ComponentModel;
using System.Data.Entity;
using System.ComponentModel.DataAnnotations;

namespace EFTest.Models.Part2
{
    [Table("Catalog")]
    public class Catalog
    {
        [Key]
        public int CatalogId { get; set; }
        public string Name { get; set; }

    }
}

2.数据访问层

using System;
using System.Data.Objects;
using System.Data.Objects.DataClasses;
using System.Data.EntityClient;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;

namespace EFTest.Models.Part2
{
   
   
    public partial class DbContextFactory : DbContext
    {
        public DbSet<Book> Books { get; set; }
        public DbSet<Catalog> Catalogs { get; set; } 
    }
}

web.config加入以下配置

  <connectionStrings>
    <add name="DbContextFactory"
providerName="System.Data.SqlClient"
connectionString="Server=(local);initial catalog=TestEF;user id=sa;password=abc123_;"/>

  </connectionStrings>

数据增加、删除、修改

Book book = new Book
{
BookName = "kenny",
CatalogId = 3
};
using (var context = new DbContextFactory())
{
context.Books.Add(book);
context.SaveChanges();//增加
               

book = context.Books.Find(2);
context.Books.Remove(book);//删除
context.SaveChanges();

book = context.Books.Find(2);
book.BookName = "ss";
context.SaveChanges();//修改

}