实体类数据访问类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1.App_Code
{
    public class Users//权限提升 在class前面加public
    {
        //吧表的内容腾进来快捷键Ctrl+r+e
        //过程只用到封装。
        private string _Ids;

        public string Ids
        {
            get { return _Ids; }
            set { _Ids = value; }
        }
        private string _Ucode;

        public string Ucode
        {
            get { return _Ucode; }
            set { _Ucode = value; }
        }
        private string _UserName;

        public string UserName
        {
            get { return _UserName; }
            set { _UserName = value; }
        }
        private string _PassWord;

        public string PassWord
        {
            get { return _PassWord; }
            set { _PassWord = value; }
        }
        private string _NickName;

        public string NickName
        {
            get { return _NickName; }
            set { _NickName = value; }
        }
        private bool _Sex;

        public bool Sex
        {
            get { return _Sex; }
            set { _Sex = value; }
        }
        private DateTime _Birthday;

        public DateTime Birthday
        {
            get { return _Birthday; }
            set { _Birthday = value; }
        }
        private string _Nation;

        public string Nation
        {
            get { return _Nation; }
            set { _Nation = value; }
        }



    }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;

namespace ConsoleApplication1.App_Code
{
    public class UsersData//提升权限
    {
        //两个对象但并没有实例化
        SqlConnection conn;
        SqlCommand cmd;

        public UsersData()//2、构造函数
        {
            conn = new SqlConnection("server=.;database=Data0504;user=sa;pwd=123;");
            cmd = conn.CreateCommand();
        }
        //查询全部
        public List<Users> SelectAll()
        {
            List<Users> ulist = new List<Users>();//创建一个Users的泛型集合。作用：将查到的数据放到集合里
            cmd.CommandText = "select *from Users";

            conn.Open();
            SqlDataReader dr = cmd.ExecuteReader();
            while (dr.Read())//数据很多判断dr.Read()是true进来读一行如果fales没有数据结束循环
            {
                Users u = new Users();//创建users对象
                u.Ids = dr["Ids"].ToString();//将读出来的数据dr中的ids赋值给新对象u.ids
                u.Ucode = dr["Ucode"].ToString();
                u.UserName = dr["UserName"].ToString();
                u.PassWord = dr["PassWord"].ToString();
                u.NickName = dr["NickName"].ToString();
                u.Sex = Convert.ToBoolean(dr["Sex"]);
                u.Birthday = Convert.ToDateTime(dr["Birthday"]);
                u.Nation = dr["Nation"].ToString();

                ulist.Add(u);//将新对象u里面的数据添加到ulist里
            }
            conn.Close();
            return ulist;//返回ulist
        }

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication1.App_Code
{
    public class Test1
    {

        /// <summary>
        /// 将Users表数据展示出来
        /// </summary>
        public void DataLook()
        {
            List<Users> list = new UsersData().SelectAll();//取出查看数据的List<Users>集合需要引用命名空间。=new UsersData().SelectAll() 创建类的名称下的查看方法的名字
            Console.WriteLine("ids    编号    用户名     密码    昵称");
            foreach (Users u in list)//遍历下list集合
            {
                Console.WriteLine(u.Ids + "    " + u.Ucode + "    " + u.UserName + "    " + u.PassWord + "    " + u.NickName);
            }
        }
    }
}