经典总结:数据访问类继承于基类

using System;
using System.Data;
using System.Data.Common;
using System.Configuration;
using System.Collections.Generic;
using Config;
using Model;

namespace DeviceManager.DAL
{
    public class UserDataAccess : DataAccessObject
    {
        private static UserDataAccess m_instance;
        public UserDataAccess() : base(MineConfig.GetConStr(), MineConfig.providerName()) { }
        public static UserDataAccess Instance
        {
            get
            {
                if (m_instance == null)
                {
                    m_instance = new UserDataAccess();
                }
                return m_instance;
            }
        }

        private User GetUserClass(DbDataReader read)
        {
            User c = new User();
            try
            {
                c.ID = (int)read["ID"];
                c.UserName = read["UserName"].ToString();
                c.UserCategory = (int)read["Usercategory"];
                c.PassWord = read["PassWord"].ToString();
                return c;
            }
            catch 
            {
                throw new Exception("User对象创建失败，数据库访问失败或数据不完整");
            }        
        }
        public List<User> GetUserList()
        {
            List<User> c = new List<User>();
            try
            {
                using (DbDataReader reader = ExecuteReader(CommandType.StoredProcedure, "UP_User_GetList"))
                {
                    while (reader.Read())
                    {
                        c.Add(GetUserClass(reader));
                    }
                }
                return c;
            }
            catch
            {
                throw new Exception("获取用户列表失败");
            }
        }
        public User GetUser(string userName)
        {
            User c = new User();
            try
            {
                DbParameter pUserName = CreateParameter("UserName", DbType.String);
                pUserName.Value = userName;

                using (DbDataReader reader = ExecuteReader(CommandType.StoredProcedure, "GetUserByUserName", pUserName))
                {
                    while (reader.Read())
                    {
                        c = GetUserClass(reader);
                    }
                }
                return c;
            }
            catch(Exception ex)
            { throw ex; }
        }
        public bool DeleteUser(int id)
        {
            try
            {
                DbParameter pId = CreateParameter("ID", DbType.Int32);
                pId.Value = id;
                int rest = ExecuteNonQuery(CommandType.StoredProcedure, "pId", pId);
                return (rest == 1);
            }
            catch(Exception ex)
            {
                throw ex;
            }
        }
        public bool CreateUser(string userName, string passWrod,int userCategory)
        {
            try
            {
                DbParameter pUserName = CreateParameter("UserName", DbType.String);
                pUserName.Value = userName;
                DbParameter pPawwWord = CreateParameter("PassWord", DbType.String);
                pPawwWord.Value = passWrod;
                DbParameter pUserCategory = CreateParameter("UserCategory", DbType.Int32);
                pUserCategory.Value = userCategory;
                int rest = ExecuteNonQuery(CommandType.StoredProcedure, "UP_User_ADD", pUserName, pPawwWord, pUserCategory);
                return (rest == 1);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        public bool UpDataUser(string userName, string passWrod, int userCategory)
        {
            try
            {
                DbParameter pUserName = CreateParameter("UserName", DbType.String);
                pUserName.Value = userName;
                DbParameter pPawwWord = CreateParameter("PassWord", DbType.String);
                pPawwWord.Value = passWrod;
                DbParameter pUserCategory = CreateParameter("UserCategory", DbType.Int32);
                pUserCategory.Value = userCategory;
                int rest = ExecuteNonQuery(CommandType.StoredProcedure, "UP_User_Update", pUserName, pPawwWord, pUserCategory);
                return (rest == 1);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
        public bool IsUserName(string userName)
        {
            try
            {
                DbParameter pUserName = CreateParameter("UserName", DbType.String);
                pUserName.Value = userName;
                int rest = (int)ExecuteScalar(CommandType.StoredProcedure, "UP_User_Exists",pUserName);
                return (rest >= 1);
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }
      
        
    }
}