ADO.NET与ORM的比较(3)Linq to SQL实现CRUD
http://blog.51cto.com/images/editer/InBlock.gif using System;http://blog.51cto.com/images/editer/InBlock.gif using System.Collections.Generic;http://blog.51cto.com/images/editer/InBlock.gif using System.Linq;
http://blog.51cto.com/images/editer/InBlock.gif using System.Text;
http://blog.51cto.com/images/editer/InBlock.gif using System.Data.SqlClient;
http://blog.51cto.com/images/editer/InBlock.gif using System.Data.Linq;
http://blog.51cto.com/images/editer/InBlock.gif using System.Configuration;
http://blog.51cto.com/images/editer/InBlock.gif
http://blog.51cto.com/images/editer/InBlock.gif namespace LinqDemo
http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 说明：这个类是为了演示.NET中的Linq to SQL的用法
http://blog.51cto.com/images/editer/InBlock.gif /// 作者：周公（周金桥）
http://blog.51cto.com/images/editer/InBlock.gif /// 日期：2010-03-01
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif public>http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 统计用户总数
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif public int Count()
http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif方法一#region 方法一
http://blog.51cto.com/images/editer/InBlock.gif //使用SqlConnection来实例化DataContext对象
http://blog.51cto.com/images/editer/InBlock.gif SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["LinqDemo.Properties.Settings.AspNetStudyConnectionString"].ConnectionString);
http://blog.51cto.com/images/editer/InBlock.gif DataContext context = new DataContext(connection);
http://blog.51cto.com/images/editer/InBlock.gif IEnumerable collection = context.ExecuteQuery("select count(1) from UserInfo");
http://blog.51cto.com/images/editer/InBlock.gif int count = collection.ElementAt(0);
http://blog.51cto.com/images/editer/InBlock.gif return count;
http://blog.51cto.com/images/editer/InBlock.gif #endregion
http://blog.51cto.com/images/editer/InBlock.gif
http://blog.51cto.com/images/editer/InBlock.gif方法二#region 方法二
http://blog.51cto.com/images/editer/InBlock.gif //UserInfoDataClassesDataContext context = new UserInfoDataClassesDataContext();
http://blog.51cto.com/images/editer/InBlock.gif ////return context.UserInfo.Count(item => item.Age > 23);//带条件统计
http://blog.51cto.com/images/editer/InBlock.gif //return context.UserInfo.Count();
http://blog.51cto.com/images/editer/InBlock.gif #endregion
http://blog.51cto.com/images/editer/InBlock.gif }
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 创建用户
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 用户实体
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif public void Create(UserInfo info)
http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif UserInfoDataClassesDataContext context = new UserInfoDataClassesDataContext();
http://blog.51cto.com/images/editer/InBlock.gif context.UserInfo.InsertOnSubmit(info);
http://blog.51cto.com/images/editer/InBlock.gif context.SubmitChanges();
http://blog.51cto.com/images/editer/InBlock.gif }
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 读取用户信息
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 用户编号
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif public UserInfo Read(int userId)
http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif UserInfoDataClassesDataContext context = new UserInfoDataClassesDataContext();
http://blog.51cto.com/images/editer/InBlock.gif context.Log = Console.Out;
http://blog.51cto.com/images/editer/InBlock.gif var query = from item in context.UserInfo
http://blog.51cto.com/images/editer/InBlock.gif where item.UserID == userId
http://blog.51cto.com/images/editer/InBlock.gif select item;
http://blog.51cto.com/images/editer/InBlock.gif return query.First();
http://blog.51cto.com/images/editer/InBlock.gif }
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 更新用户信息
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 用户实体
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif public void Update(UserInfo info)
http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif UserInfoDataClassesDataContext context = new UserInfoDataClassesDataContext();
http://blog.51cto.com/images/editer/InBlock.gif UserInfo ui = context.UserInfo.First(item => item.UserID == info.UserID);
http://blog.51cto.com/images/editer/InBlock.gif ui.Age = info.Age;
http://blog.51cto.com/images/editer/InBlock.gif ui.Email = info.Email;
http://blog.51cto.com/images/editer/InBlock.gif ui.Mobile = info.Mobile;
http://blog.51cto.com/images/editer/InBlock.gif ui.Phone = info.Phone;
http://blog.51cto.com/images/editer/InBlock.gif ui.RealName = info.RealName;
http://blog.51cto.com/images/editer/InBlock.gif ui.Sex = info.Sex;
http://blog.51cto.com/images/editer/InBlock.gif ui.UserName = info.UserName;
http://blog.51cto.com/images/editer/InBlock.gif context.SubmitChanges();
http://blog.51cto.com/images/editer/InBlock.gif }
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 删除用户
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 用户编号
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif public void Delete(int userId)
http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif方法一#region 方法一
http://blog.51cto.com/images/editer/InBlock.gif //UserInfoDataClassesDataContext context = new UserInfoDataClassesDataContext();
http://blog.51cto.com/images/editer/InBlock.gif //context.ExecuteCommand("delete from UserInfo where UserId=" + userId);
http://blog.51cto.com/images/editer/InBlock.gif #endregion
http://blog.51cto.com/images/editer/InBlock.gif方法二#region 方法二
http://blog.51cto.com/images/editer/InBlock.gif UserInfoDataClassesDataContext context = new UserInfoDataClassesDataContext();
http://blog.51cto.com/images/editer/InBlock.gif UserInfo ui = context.UserInfo.First(item => item.UserID == userId);
http://blog.51cto.com/images/editer/InBlock.gif context.UserInfo.DeleteOnSubmit(ui);
http://blog.51cto.com/images/editer/InBlock.gif context.SubmitChanges();
http://blog.51cto.com/images/editer/InBlock.gif #endregion
http://blog.51cto.com/images/editer/InBlock.gif }
http://blog.51cto.com/images/editer/InBlock.gif
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 删除用户
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 用户实体
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif public void Delete(UserInfo info)
http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif UserInfoDataClassesDataContext context = new UserInfoDataClassesDataContext();
http://blog.51cto.com/images/editer/InBlock.gif var userList = from Users
http://blog.51cto.com/images/editer/InBlock.gif in context.UserInfo
http://blog.51cto.com/images/editer/InBlock.gif where Users.UserID == info.UserID
http://blog.51cto.com/images/editer/InBlock.gif select Users;
http://blog.51cto.com/images/editer/InBlock.gif foreach (var user in userList)
http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif context.UserInfo.DeleteOnSubmit(user);
http://blog.51cto.com/images/editer/InBlock.gif }
http://blog.51cto.com/images/editer/InBlock.gif //context.UserInfo.DeleteOnSubmit(userList.First());
http://blog.51cto.com/images/editer/InBlock.gif //注意下面的写法是错误的
http://blog.51cto.com/images/editer/InBlock.gif // context.UserInfo.DeleteOnSubmit(info);
http://blog.51cto.com/images/editer/InBlock.gif context.SubmitChanges();
http://blog.51cto.com/images/editer/InBlock.gif }
http://blog.51cto.com/images/editer/InBlock.gif
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif /// 获取用户表中编号最大的用户
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif ///
http://blog.51cto.com/images/editer/InBlock.gif public int GetMaxUserId()
http://blog.51cto.com/images/editer/InBlock.gif {
http://blog.51cto.com/images/editer/InBlock.gif UserInfoDataClassesDataContext context = new UserInfoDataClassesDataContext();
http://blog.51cto.com/images/editer/InBlock.gif int userId=context.UserInfo.Max(item => item.UserID);
http://blog.51cto.com/images/editer/InBlock.gif return userId;
http://blog.51cto.com/images/editer/InBlock.gif }
http://blog.51cto.com/images/editer/InBlock.gif }
http://blog.51cto.com/images/editer/InBlock.gif }
页:
[1]