3.EF 6.0 Code-First实现增删查改
或者：http://www.codeproject.com/Articles/640302/CRUD-Operations-Using-Entity-Framework-Code-Fi
系列目录：
- Relationship in Entity Framework Using Code First Approach With Fluent API【【使用EF Code-First方式和Fluent API来探讨EF中的关系】】
- Code First Migrations with Entity Framework【使用EF 做数据库迁移】
- CRUD Operations Using Entity Framework 5.0 Code First Approach in MVC【在MVC中使用EF 5.0做增删查改】
- CRUD Operations Using the Repository Pattern in MVC【在MVC中使用仓储模式，来做增删查改】
- CRUD Operations Using the Generic Repository Pattern and Unit of Work in MVC【在MVC中使用泛型仓储模式和工作单元来做增删查改】
- CRUD Operations Using the Generic Repository Pattern and Dependency Injection in MVC【在MVC中使用泛型仓储模式和依赖注入，来做增删查改】
本来不想写这篇的，因为感觉增删查改，实在是太Easy了。好了，为了巩固学习，还是继续吧：
打算实现书籍的增删查改，有两个实体，一个是Book【书籍实体】，另外一个是出版商实体【Publisher】，一个出版商可以出版很多书籍，一本书只能是由一个出版商出版。所以，书籍和出版商之间是一对多的关系。
先来看看整个项目的结构吧：
Entity实体中：
BaseEntity实体：【日期使用了数据注解，这样在显示的时候，就有格式了。】
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace EF.Entity
{
public abstract class BaseEntity
{ /// <summary>
/// ID
/// </summary>
public int ID { get; set; } /// <summary>
/// 添加时间
/// </summary>
///
[DataType(DataType.Date)]
[DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
public DateTime AddedDate { get; set; } /// <summary>
/// 修改时间
/// </summary>
///
[DataType(DataType.Date)]
[DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
public DateTime ModifiedDate { get; set; }
}
}
Book实体：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace EF.Entity
{
/// <summary>
/// Book实体
/// </summary>
public class Book:BaseEntity
{
/// <summary>
/// 书名
/// </summary>
public string BookName { get; set; } /// <summary>
/// 书的作者
/// </summary>
public string BookAuthor { get; set; } /// <summary>
/// 书的价格
/// </summary>
public decimal BookPrice { get; set; } /// <summary>
/// 出版商编号
/// </summary>
public int PublisherId { get; set; } /// <summary>
/// 导航属性---出版商
/// </summary>
public virtual Publisher Publisher { get; set; }
}
}
出版商实体：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text; namespace EF.Entity
{
public class Publisher:BaseEntity
{
/// <summary>
/// 出版商的名字
/// </summary>
public string PublisherName { get; set; } /// <summary>
/// 导航属性
/// </summary>
public virtual ICollection<Book> Books { get; set; }
}
}
然后在EF.Data项目中：
BookMap类：
using EF.Entity;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity.ModelConfiguration;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace EF.Data
{
public class BookMap:EntityTypeConfiguration<Book>
{
public BookMap()
{
//配置主键
this.HasKey(s => s.ID);
//配置字段
this.Property(s => s.ID).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
this.Property(s => s.BookName).HasColumnType("nvarchar").HasMaxLength().IsRequired();
// this.Property(s => s.BookAuthor).HasColumnType("nvarchar(50)").IsRequired();//注意这个和BookName字段配置的区别之处:这样写EF生成不了数据库
this.Property(s => s.BookAuthor).HasColumnType("nvarchar").HasMaxLength().IsRequired();
this.Property(s => s.BookPrice).IsRequired();
this.Property(s => s.AddedDate).IsRequired();
this.Property(s => s.ModifiedDate).IsRequired();
this.Property(s => s.PublisherId).IsRequired(); //配置关系[一个出版商可以出版很多书籍]【外键单独配置，不是必须在Property中配置，当然也可以在Property中配置】
this.HasRequired(s => s.Publisher).WithMany(s => s.Books).HasForeignKey(s => s.PublisherId).WillCascadeOnDelete(true); //配置表名字
this.ToTable("Books"); }
}
}
PublisherMap类：
using EF.Entity;
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity.ModelConfiguration;
using System.Linq;
using System.Text;
using System.Threading.Tasks; namespace EF.Data
{
public class PublisherMap:EntityTypeConfiguration<Publisher>
{
public PublisherMap()
{
//配置主键
this.HasKey(s => s.ID);
this.Property(s => s.ID).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Identity);
// this.Property(s => s.PublisherName).HasColumnType("nvarchar(50)").IsRequired();//这样写，有问题，生成不了数据库
this.Property(s => s.PublisherName).HasColumnType("nvarchar").HasMaxLength().IsRequired();
this.Property(s => s.AddedDate).IsRequired();
this.Property(s => s.ModifiedDate).IsRequired(); }
}
}
出版商我这里不做增删查改，到时候手动添加几条数据进去，然后在Book的视图中，把出版商做成下拉框的样式：所以我这里额外添加一个实体：【PublisherModel实体中的构造函数里的初始化属性嗲吗，不能忘记！！！】
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web;
using System.Web.Mvc; namespace EF.Web.Models
{
public class PublisherModel
{
public PublisherModel()
{
PublisherList = new List<SelectListItem>();
} [Display(Name="PublisherName")]
public int PublisherID { get; set; } public List<SelectListItem> PublisherList { get; set; }
}
}
数据上下文类：
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks; namespace EF.Data
{
public class EFDbContext:DbContext
{
public EFDbContext()
: base("name=DbConnectionString")
{ } protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
var typesToRegister = Assembly.GetExecutingAssembly().GetTypes()
.Where(type => !String.IsNullOrEmpty(type.Namespace))
.Where(type => type.BaseType != null && type.BaseType.IsGenericType
&& type.BaseType.GetGenericTypeDefinition() == typeof(EntityTypeConfiguration<>));
foreach (var type in typesToRegister)
{
dynamic configurationInstance = Activator.CreateInstance(type);
modelBuilder.Configurations.Add(configurationInstance);
}
//base.OnModelCreating(modelBuilder);
}
}
}
Ef.Data项目和Web项目中都要加上连接字符串：
<connectionStrings>
<add name="DbConnectionString" connectionString="Server=.;Database=EFCURDDB;uid=sa;Pwd=Password_1" providerName="System.Data.SqlClient"/>
</connectionStrings>
现在看看Web项目：
using EF.Data;
using EF.Entity;
using EF.Web.Models;
using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
using System.Web.Mvc; namespace EF.Web.Controllers
{
public class BookController : Controller
{
private EFDbContext db;
public BookController()
{
db = new EFDbContext();
}
#region 列表
/// <summary>
/// 列表
/// </summary>
/// <returns></returns>
public ActionResult Index()
{
return View(db.Set<Book>().ToList());
}
#endregion #region AddBook
/// <summary>
/// 添加Book
/// </summary>
/// <returns></returns>
public ActionResult AddBook()
{
PublisherModel model = new PublisherModel();
List<Publisher> listPublisher = db.Set<Publisher>().ToList(); foreach (var item in listPublisher)
{
model.PublisherList.Add(new SelectListItem()
{
Text = item.PublisherName,
Value = item.ID.ToString() });
} ViewBag.PublishedList = model.PublisherList; return View();
} /// <summary>
/// 添加Book
/// </summary>
/// <returns></returns>
[HttpPost]
public ActionResult AddBook([Bind(Include = "BookName,BookAuthor,BookPrice,AddedDate,ModifiedDate,PublisherId")] Book model)
{
Book addBook = new Book() {
AddedDate=model.AddedDate,
BookAuthor=model.BookAuthor,
BookName=model.BookName,
BookPrice=model.BookPrice,
ModifiedDate=model.ModifiedDate,
PublisherId = Convert.ToInt32( Request["PublishedName"].ToString())
//这里因为出版商我用的是另外的Model，视图中使用模型绑定只能用一个Model，所以修改和添加只能这样搞了。 };
db.Entry(addBook).State = EntityState.Added;
db.SaveChanges();
return RedirectToAction("Index");
}
#endregion #region UpdateBook
/// <summary>
/// 修改Book
/// </summary>
/// <param name="bookId"></param>
/// <returns></returns>
public ActionResult UpdateBook(int bookId)
{
PublisherModel model = new PublisherModel();
List<Publisher> listPublisher = db.Set<Publisher>().ToList(); foreach (var item in listPublisher)
{
model.PublisherList.Add(new SelectListItem()
{
Text = item.PublisherName,
Value = item.ID.ToString() });
} ViewBag.PublishedList = model.PublisherList; Book bookModel = db.Set<Book>().Where(s => s.ID == bookId).FirstOrDefault();
return View(bookModel);
} /// <summary>
/// 修改Book
/// </summary>
/// <param name="model"></param>
/// <returns></returns>
[HttpPost]
public ActionResult UpdateBook([Bind(Include = "ID,BookName,BookAuthor,BookPrice,AddedDate,ModifiedDate,PublisherId")] Book model) //注意这里一定别忘记绑定 ID列哦
{
Book bookModel = db.Set<Book>().Where(s => s.ID == model.ID).FirstOrDefault(); if (bookModel != null)
{
Book updatemodel = new Book() {
AddedDate = model.AddedDate,
BookAuthor = model.BookAuthor,
ID = model.ID,
ModifiedDate = model.ModifiedDate,
BookName = model.BookName,
BookPrice = model.BookPrice,
PublisherId = Convert.ToInt32(Request["PublishedName"].ToString())//这里因为出版商我用的是另外的Model，视图中使用模型绑定只能用一个Model，所以修改和添加只能这样搞了。
};
db.Entry(bookModel).CurrentValues.SetValues(updatemodel); //保存的另外一种方式
db.SaveChanges();
return RedirectToAction("Index");
}
else
{
return View(model);
} #region 保存的方式二
//db.Entry(model).State = EntityState.Modified;
//db.SaveChanges();
//return RedirectToAction("Index");
#endregion
}
#endregion #region DeleteBook
public ActionResult DeleteBook(int bookId)
{
Book model = db.Set<Book>().Where(s => s.ID == bookId).FirstOrDefault();
return View(model);
} [HttpPost]
public ActionResult DeleteBook(int bookId, FormCollection form)
{
Book model = db.Set<Book>().Where(s => s.ID == bookId).FirstOrDefault();
db.Entry(model).State = EntityState.Deleted;
db.SaveChanges();
return RedirectToAction("Index");
}
#endregion }
}
视图代码，我使用MVC模板生成：【适当做修改】
AddBook视图：
@model EF.Entity.Book
@{
ViewBag.Title = "AddBook";
}
<h2>AddBook</h2>
@using (Html.BeginForm("AddBook","Book",FormMethod.Post))
{
@Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Book</h4>
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
<div class="form-group">
@Html.LabelFor(model => model.AddedDate, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.AddedDate, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.AddedDate, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.ModifiedDate, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.ModifiedDate, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.ModifiedDate, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.BookName, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.BookName, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.BookName, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.BookAuthor, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.BookAuthor, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.BookAuthor, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.BookPrice, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.BookPrice, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.BookPrice, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.PublisherId, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownList("PublishedName", ViewData["PublishedList"] as List<SelectListItem>)
@*@Html.EditorFor(model => model.PublisherId, new { htmlAttributes = new { @class = "form-control" } })*@
@Html.ValidationMessageFor(model => model.PublisherId, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Create" class="btn btn-default" />
</div>
</div>
</div>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
<script src="~/Scripts/jquery-1.10.2.min.js"></script>
<script src="~/Scripts/jquery.validate.min.js"></script>
<script src="~/Scripts/jquery.validate.unobtrusive.min.js"></script>
UpdateBook视图：
@model EF.Entity.Book
@{
ViewBag.Title = "UpdateBook";
}
<h2>UpdateBook</h2>
@using (Html.BeginForm("UpdateBook","Book",FormMethod.Post))
{
@Html.AntiForgeryToken()
<div class="form-horizontal">
<h4>Book</h4>
<hr />
@Html.ValidationSummary(true, "", new { @class = "text-danger" })
@Html.HiddenFor(model => model.ID)
<div class="form-group">
@Html.LabelFor(model => model.AddedDate, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.AddedDate, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.AddedDate, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.ModifiedDate, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.ModifiedDate, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.ModifiedDate, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.BookName, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.BookName, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.BookName, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.BookAuthor, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.BookAuthor, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.BookAuthor, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.BookPrice, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.EditorFor(model => model.BookPrice, new { htmlAttributes = new { @class = "form-control" } })
@Html.ValidationMessageFor(model => model.BookPrice, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
@Html.LabelFor(model => model.PublisherId, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownList("PublishedName", ViewData["PublishedList"] as List<SelectListItem>)
@*@Html.EditorFor(model => model.PublisherId, new { htmlAttributes = new { @class = "form-control" } })*@
@Html.ValidationMessageFor(model => model.PublisherId, "", new { @class = "text-danger" })
</div>
</div>
<div class="form-group">
<div class="col-md-offset-2 col-md-10">
<input type="submit" value="Save" class="btn btn-default" />
</div>
</div>
</div>
}
<div>
@Html.ActionLink("Back to List", "Index")
</div>
<script src="~/Scripts/jquery-1.10.2.min.js"></script>
<script src="~/Scripts/jquery.validate.min.js"></script>
<script src="~/Scripts/jquery.validate.unobtrusive.min.js"></script>
注意:这里我只是把有改动的视图贴了出来，其他的视图，根据MVC模板生成之后，就不用管了。
@model IEnumerable<EF.Entity.Book>
@{
ViewBag.Title = "Index";
}
<h2>Index</h2>
<p>
@Html.ActionLink("Create New", "AddBook")
</p>
<table class="table">
<tr>
<th>
@Html.DisplayNameFor(model => model.AddedDate)
</th>
<th>
@Html.DisplayNameFor(model => model.ModifiedDate)
</th>
<th>
@Html.DisplayNameFor(model => model.BookName)
</th>
<th>
@Html.DisplayNameFor(model => model.BookAuthor)
</th>
<th>
@Html.DisplayNameFor(model => model.BookPrice)
</th>
<th>
@Html.DisplayNameFor(model => model.PublisherId)
</th>
<th></th>
</tr>
@foreach (var item in Model) {
<tr>
<td>
@Html.DisplayFor(modelItem => item.AddedDate)
</td>
<td>
@Html.DisplayFor(modelItem => item.ModifiedDate)
</td>
<td>
@Html.DisplayFor(modelItem => item.BookName)
</td>
<td>
@Html.DisplayFor(modelItem => item.BookAuthor)
</td>
<td>
@Html.DisplayFor(modelItem => item.BookPrice)
</td>
<td>
@Html.DisplayFor(modelItem => item.PublisherId)
</td>
<td>
@Html.ActionLink("Edit", "UpdateBook", new { bookId = item.ID }) |
@Html.ActionLink("Details", "DetailsBook", new { bookId = item.ID }) |
@Html.ActionLink("Delete", "DeleteBook", new { bookId = item.ID })
</td>
</tr>
}
</table>
效果图：
总结：1.下拉框实体中，构造函数初始化语句不能忘记。
2.修改的方式，有新变化看代码；
3.模型绑定的时候，特别要注意，Bind的字段，修改的时候，Bind字段ID不能少。
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