[EF]使用EF简单增删改查

认识EF

ADO.NET Entity Framework 是微软以ADO.NET为基础所发展出来的对象关系对伊（O/R Mapping）解决方案，早起被称为ObjectSpage，最新版本EF6。

实体框架Entity Framework是ADO.NET中的一组支持面向数据的软件应用程序的技术。是微软的一个ORM框架。

什么是O/R Mapping

广义上，ORM指的是面向对象模型和关系数据库的数据结构之间的相互转换。

狭义上，ORM可以被认为是，基于关系数据库的数据存储，实现一个虚拟的面向对象的数据访问接口。理想情况下，基于这样一个面向对象的接口，持久化一个OO对象应该不需要了解任何关系型数据存储数据的实现细节。

添加数据

测试用数据库

 USE [Wolfy.Shop]

 GO

 /****** Object:  Table [dbo].[TB_Customer]    Script Date: 2014/7/29 20:01:56 ******/

 SET ANSI_NULLS ON

 GO

 SET QUOTED_IDENTIFIER ON

 GO

 CREATE TABLE [dbo].[TB_Customer](

     [ID] [uniqueidentifier] NOT NULL,

     [Name] [nvarchar](32) NULL,

     [Address] [nvarchar](100) NULL,

     [Gender] [bit] NULL,

  CONSTRAINT [PK_CustomerID] PRIMARY KEY CLUSTERED

 (

     [ID] ASC

 )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

 ) ON [PRIMARY]

 GO

TB_Customer

 USE [Wolfy.Shop]

 GO

 /****** Object:  Table [dbo].[TB_Order]    Script Date: 2014/7/29 20:02:47 ******/

 SET ANSI_NULLS ON

 GO

 SET QUOTED_IDENTIFIER ON

 GO

 CREATE TABLE [dbo].[TB_Order](

     [ID] [int] NOT NULL,

     [OrderName] [nvarchar](1000) NULL,

     [CreateDate] [datetime] NULL,

     [customerId] [uniqueidentifier] NULL,

  CONSTRAINT [PK_TB_Order] PRIMARY KEY CLUSTERED

 (

     [ID] ASC

 )WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]

 ) ON [PRIMARY]

 GO

 ALTER TABLE [dbo].[TB_Order]  WITH CHECK ADD  CONSTRAINT [FK_Customer_Order] FOREIGN KEY([customerId])

 REFERENCES [dbo].[TB_Customer] ([ID])

 GO

 ALTER TABLE [dbo].[TB_Order] CHECK CONSTRAINT [FK_Customer_Order]

 GO

TB_Order

工具VS2013,SQL SERVER2012
在使用EF的时候发现，跟之前的版本差别还是挺大的，有些方法的名字都改了。这里记录一下，使用的时候方便查找吧。

测试页面

 <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="AddCustomer.aspx.cs" Inherits="Wofly.EFDemo.AddCustomer" %>

 <!DOCTYPE html>

 <html xmlns="http://www.w3.org/1999/xhtml">

 <head runat="server">

     <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

     <title></title>

 </head>

 <body>

     <form id="form1" runat="server">

         <div>

             <asp:Button Text="添加" CommandArgument="add" runat="server" ID="btnAdd" OnClick="btnAdd_Click" />

             <table>

                 <tr>

                     <td>用户名：</td>

                     <td>

                         <asp:TextBox runat="server" ID="txtUserName" ClientIDMode="Static" /></td>

                 </tr>

                 <tr>

                     <td>用户地址：</td>

                     <td>

                         <asp:TextBox runat="server" ID="txtAddress" ClientIDMode="Static" /></td>

                 </tr>

                 <tr>

                     <td>性别：</td>

                     <td>

                         <asp:RadioButton runat="server" Checked="true" ID="rdbMan" Text="男" GroupName="gender" />

                         <asp:RadioButton GroupName="gender" runat="server" ID="rdbFemale" Text="女" />

                     </td>

                 </tr>

             </table>

             <asp:Repeater runat="server" ID="rptCustomerList">

                 <HeaderTemplate>

                     <table>

                         <tr>

                             <th>序号</th>

                             <th>用户名</th>

                             <th>地址</th>

                             <th>性别</th>

                             <th>操作</th>

                         </tr>

                 </HeaderTemplate>

                 <ItemTemplate>

                     <tr>

                         <td><%#Container.ItemIndex+1 %></td>

                         <td><%#Eval("Name") %></td>

                         <td><%#Eval("Address") %></td>

                         <td><%#Convert.ToBoolean(Eval("Gender"))==true?"男":"女" %></td>

                         <td>

                             <asp:LinkButton Text="编辑" runat="server" OnClick="lnkEdit_Click" CommandName="Edit" CommandArgument='<%#Eval("ID") %>' ID="lnkEdit" /><asp:LinkButton Text="删除" runat="server" OnClick="lnkEdit_Click" ID="lnkDelete" CommandName="Delete" CommandArgument='<%#Eval("ID") %>' /></td>

                     </tr>

                 </ItemTemplate>

                 <FooterTemplate>

                     </table>

                 </FooterTemplate>

             </asp:Repeater>

         </div>

     </form>

 </body>

 </html>

AddCustomer.aspx

增加用户

                ShopEntities shopEntities = new ShopEntities();

                 TB_Customer tb_CustomerAdd = new TB_Customer() { ID = Guid.NewGuid(), Name = txtUserName.Text, Address = txtAddress.Text, Gender = rdbMan.Checked ? true : false };

                 shopEntities.TB_Customer.Add(tb_CustomerAdd);

                 int intResult = shopEntities.SaveChanges();

                 if (intResult > )

                 {

                     DataInit();

                 }

删除数据

                    shopEntities.TB_Customer.Remove(tb_Customer);

                     if (shopEntities.SaveChanges() > )

                     {

                         this.DataInit();

                     }

修改数据

                 ShopEntities shopEntities = new ShopEntities();

                 var customer = from c in shopEntities.TB_Customer

                                where c.ID == new Guid(btn.CommandArgument)

                                select c;

                 TB_Customer tb_CustomerUpdate = customer.FirstOrDefault<TB_Customer>();

                 //将 对象 添加到 EF中

                 tb_CustomerUpdate.Name = txtUserName.Text;

                 tb_CustomerUpdate.Address = txtAddress.Text;

                 tb_CustomerUpdate.Gender = rdbMan.Checked ? true : false;

                 //是否修改

                 shopEntities.Entry<TB_Customer>(tb_CustomerUpdate).State = System.Data.EntityState.Modified;

                 //一次性 生成sql语句到数据库执行

                 shopEntities.SaveChanges();

查询数据

         private void DataInit()

         {

             ShopEntities shopEntities = new ShopEntities();

             var customers = from c in shopEntities.TB_Customer

                             select c;

             this.rptCustomerList.DataSource = customers.ToList();

             this.rptCustomerList.DataBind();

         }

总结

新技术更新可真快，这里只是记录增删改查的方法，也没具体描述，只是影响中感觉跟ef4差别很大。这里记录一下，使用起来的时候，希望能快速上手。