EntityFrameWork.doc

一、首先创建两张表，产品表T_Product和T_ProClass在这里，我们把两张表的关系，主外键设置好二、现在我们通过vs2012添加Entity Framework选择ADO.NET实体数据模型，添加选择从数据库生成连接成功单击完成后，会生成如图所示的实体模型我们可以看到在项目中生成了两个文件Model.edmx和Model.Designer.cs这两个文件分别用来描述实体以及他们之间关系，和自动生成的C#代码，包括实体类的代码以及他们之间的代码三、框架已经搭建好，现在我们就可以通过linq语法实现对数据的查询，修改，删除，增加等操作了首先，我们来查询一下产品的列表在页面中使用Repeat控件用来显示数据 产品ID 产品名?称? 产品价?格? 产品类别e 代码很简单，就是一个简单的查询public partial class Index : System.Web.UI.Page EntityDataEntities ef = new EntityDataEntities(); protected void Page_Load(object sender, EventArgs e) if(!IsPostBack) ProBind(); public void ProBind() var proList = from s in ef.T_Product select s; Repeater1.DataSource = proList; Repeater1.DataBind(); 在这里我们要重点说一下，因为数据库的主外键关系已经被映射到对象中，所以我们可以通过对象直接调用和它关联的对象，在这里就是可以通过产品T_Product直接调用类别T_ProClass好，现在我们在来看看如何添加产品在页面中添加文本框和按钮 产品名?称? 产品价?格? 产品类别e 后台代码public partial class Insert : System.Web.UI.Page EntityDataEntities ef = new EntityDataEntities(); protected void Page_Load(object sender, EventArgs e) if(!IsPostBack) bindProClass(); protected void bindProClass() var query = from ps in ef.T_ProClass select ps; RadioButtonList1.DataSource = query; RadioButtonList1.DataTextField = proClassName; RadioButtonList1.DataValueField = ID; RadioButtonList1.DataBind(); protected void Button1_Click(object sender, EventArgs e) T_Product product = new T_Product(); product.ProClass =Convert.ToInt32(RadioButtonList1.SelectedValue); product.ProName = txtProName.Text; product.ProPrice = Convert.ToDecimal(txtProPrice.Text); ef.T_Product.AddObject(product); ef.SaveChanges(); ef.Dispose(); Response.Write(alert(添加成功|);location.href=Index.aspx); 修改和添加很类似页面代码： 产品名?称? 产品价?格? 产品类别e 后台的代码 EntityDataEntities ef = new EntityDataEntities(); protected void Page_Load(object sender, EventArgs e) if (!IsPostBack) int id = Convert.ToInt32(Request.QueryStringproId.ToString(); bindProClass(); ProdectById(id); protected void bindProClass() var query = from ps in ef.T_ProClass select ps; RadioButtonList1.DataSource = query; RadioButtonList1.DataTextField = proClassName; RadioButtonList1.DataValueField = ID; RadioButtonList1.DataBind(); protected void ProdectById(int id) var product = (from p in ef.T_Product where p.ID = id select p).Single(); RadioButtonList1.SelectedValue = product.ProClass.ToString(); txtProName.Text = product.ProName; txtProPrice.Text = product.ProPrice.ToString(); protected void Button1_Click(object sender, EventArgs e) int id = Convert.ToInt32(Request.QueryStringproId.ToString(); var product = (from p in ef.T_Product where p.ID = id select p).Single(); product.ProClass = Convert.ToInt32(RadioButtonList1.SelectedValue); product.ProName = txtProName.Text; product.ProPrice = Convert.ToDecimal(txtProPrice.Text); ef.SaveChanges(); ef.Dispose(); Response.Write(alert(修T改?成功|);location.href=Index.aspx); 删除的代码 EntityDataEntities ef = new EntityDataEntities(); protected void Page_Load(object sender, EventArgs e) if (!IsPostBack) int id = Convert.ToInt32(Request.QueryStringproId.ToString(); var product = (from p in ef.T_Product where p.ID = id s