/**  版本信息模板在安装目录下，可自行修改。
* electricity_data.cs
*
* 功 能： N/A
* 类 名： electricity_data
*
* Ver    变更日期             负责人  变更内容
* ───────────────────────────────────
* V0.01  2024/1/8 18:26:16   N/A    初版
*
* Copyright (c) 2012 Maticsoft Corporation. All rights reserved.
*┌──────────────────────────────────┐
*│　此技术信息为本公司机密信息，未经本公司书面同意禁止向第三方披露．　│
*│　版权所有：动软卓越（北京）科技有限公司　　　　　　　　　　　　　　│
*└──────────────────────────────────┘
*/
using System;
using System.Data;
using System.Text;
using MySql.Data.MySqlClient;
using Maticsoft.DBUtility;//Please add references
namespace DataServer.DAL
{
    /// <summary>
    /// 数据访问类:electricity_data
    /// </summary>
    public partial class electricity_data
    {
        public electricity_data()
        { }
        #region  BasicMethod

        /// <summary>
        /// 是否存在该记录
        /// </summary>
        public bool Exists(string ElectricityId)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("select count(1) from electricity_data");
            strSql.Append(" where ElectricityId=@ElectricityId ");
            MySqlParameter[] parameters = {
                    new MySqlParameter("@ElectricityId", MySqlDbType.VarChar,255)           };
            parameters[0].Value = ElectricityId;

            return DbHelperMySQL.Exists(strSql.ToString(), parameters);
        }


        /// <summary>
        /// 增加一条数据
        /// </summary>
        public bool Add(DataServer.Model.electricity_data model)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("insert into electricity_data(");
            strSql.Append("ElectricityId,DeviceId,EH,P,Kvar,Ia,Ib,Ic,Ua,Ub,Uc,ServiceRating,CreateTime,EntireTime,Reserve1,Reserve2,Reserve3,Reserve4,Reserve5)");
            strSql.Append(" values (");
            strSql.Append("@ElectricityId,@DeviceId,@EH,@P,@Kvar,@Ia,@Ib,@Ic,@Ua,@Ub,@Uc,@ServiceRating,@CreateTime,@EntireTime,@Reserve1,@Reserve2,@Reserve3,@Reserve4,@Reserve5)");
            MySqlParameter[] parameters = {
                    new MySqlParameter("@ElectricityId", MySqlDbType.VarChar,255),
                    new MySqlParameter("@DeviceId", MySqlDbType.VarChar,255),
                    new MySqlParameter("@EH", MySqlDbType.Float,255),
                    new MySqlParameter("@P", MySqlDbType.Float,255),
                    new MySqlParameter("@Kvar", MySqlDbType.Float,255),
                    new MySqlParameter("@Ia", MySqlDbType.Float,255),
                    new MySqlParameter("@Ib", MySqlDbType.Float,255),
                    new MySqlParameter("@Ic", MySqlDbType.Float,255),
                    new MySqlParameter("@Ua", MySqlDbType.Float,255),
                    new MySqlParameter("@Ub", MySqlDbType.Float,255),
                    new MySqlParameter("@Uc", MySqlDbType.Float,255),
                    new MySqlParameter("@ServiceRating", MySqlDbType.Float,255),
                    new MySqlParameter("@CreateTime", MySqlDbType.DateTime),
                    new MySqlParameter("@EntireTime", MySqlDbType.DateTime),
                    new MySqlParameter("@Reserve1", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve2", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve3", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve4", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve5", MySqlDbType.VarChar,255)};
            parameters[0].Value = model.ElectricityId;
            parameters[1].Value = model.DeviceId;
            parameters[2].Value = model.EH;
            parameters[3].Value = model.P;
            parameters[4].Value = model.Kvar;
            parameters[5].Value = model.Ia;
            parameters[6].Value = model.Ib;
            parameters[7].Value = model.Ic;
            parameters[8].Value = model.Ua;
            parameters[9].Value = model.Ub;
            parameters[10].Value = model.Uc;
            parameters[11].Value = model.ServiceRating;
            parameters[12].Value = model.CreateTime;
            parameters[13].Value = model.EntireTime;
            parameters[14].Value = model.Reserve1;
            parameters[15].Value = model.Reserve2;
            parameters[16].Value = model.Reserve3;
            parameters[17].Value = model.Reserve4;
            parameters[18].Value = model.Reserve5;

            int rows = DbHelperMySQL.ExecuteSql(strSql.ToString(), parameters);
            if (rows > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        /// <summary>
        /// 更新一条数据
        /// </summary>
        public bool Update(DataServer.Model.electricity_data model)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("update electricity_data set ");
            strSql.Append("DeviceId=@DeviceId,");
            strSql.Append("EH=@EH,");
            strSql.Append("P=@P,");
            strSql.Append("Kvar=@Kvar,");
            strSql.Append("Ia=@Ia,");
            strSql.Append("Ib=@Ib,");
            strSql.Append("Ic=@Ic,");
            strSql.Append("Ua=@Ua,");
            strSql.Append("Ub=@Ub,");
            strSql.Append("Uc=@Uc,");
            strSql.Append("ServiceRating=@ServiceRating,");
            strSql.Append("CreateTime=@CreateTime,");
            strSql.Append("EntireTime=@EntireTime,");
            strSql.Append("Reserve1=@Reserve1,");
            strSql.Append("Reserve2=@Reserve2,");
            strSql.Append("Reserve3=@Reserve3,");
            strSql.Append("Reserve4=@Reserve4,");
            strSql.Append("Reserve5=@Reserve5");
            strSql.Append(" where ElectricityId=@ElectricityId ");
            MySqlParameter[] parameters = {
                    new MySqlParameter("@DeviceId", MySqlDbType.VarChar,255),
                    new MySqlParameter("@EH", MySqlDbType.Float,255),
                    new MySqlParameter("@P", MySqlDbType.Float,255),
                    new MySqlParameter("@Kvar", MySqlDbType.Float,255),
                    new MySqlParameter("@Ia", MySqlDbType.Float,255),
                    new MySqlParameter("@Ib", MySqlDbType.Float,255),
                    new MySqlParameter("@Ic", MySqlDbType.Float,255),
                    new MySqlParameter("@Ua", MySqlDbType.Float,255),
                    new MySqlParameter("@Ub", MySqlDbType.Float,255),
                    new MySqlParameter("@Uc", MySqlDbType.Float,255),
                    new MySqlParameter("@ServiceRating", MySqlDbType.Float,255),
                    new MySqlParameter("@CreateTime", MySqlDbType.DateTime),
                    new MySqlParameter("@EntireTime", MySqlDbType.DateTime),
                    new MySqlParameter("@Reserve1", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve2", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve3", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve4", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve5", MySqlDbType.VarChar,255),
                    new MySqlParameter("@ElectricityId", MySqlDbType.VarChar,255)};
            parameters[0].Value = model.DeviceId;
            parameters[1].Value = model.EH;
            parameters[2].Value = model.P;
            parameters[3].Value = model.Kvar;
            parameters[4].Value = model.Ia;
            parameters[5].Value = model.Ib;
            parameters[6].Value = model.Ic;
            parameters[7].Value = model.Ua;
            parameters[8].Value = model.Ub;
            parameters[9].Value = model.Uc;
            parameters[10].Value = model.ServiceRating;
            parameters[11].Value = model.CreateTime;
            parameters[12].Value = model.EntireTime;
            parameters[13].Value = model.Reserve1;
            parameters[14].Value = model.Reserve2;
            parameters[15].Value = model.Reserve3;
            parameters[16].Value = model.Reserve4;
            parameters[17].Value = model.Reserve5;
            parameters[18].Value = model.ElectricityId;

            int rows = DbHelperMySQL.ExecuteSql(strSql.ToString(), parameters);
            if (rows > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// 删除一条数据
        /// </summary>
        public bool Delete(string ElectricityId)
        {

            StringBuilder strSql = new StringBuilder();
            strSql.Append("delete from electricity_data ");
            strSql.Append(" where ElectricityId=@ElectricityId ");
            MySqlParameter[] parameters = {
                    new MySqlParameter("@ElectricityId", MySqlDbType.VarChar,255)           };
            parameters[0].Value = ElectricityId;

            int rows = DbHelperMySQL.ExecuteSql(strSql.ToString(), parameters);
            if (rows > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        /// <summary>
        /// 批量删除数据
        /// </summary>
        public bool DeleteList(string ElectricityIdlist)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("delete from electricity_data ");
            strSql.Append(" where ElectricityId in (" + ElectricityIdlist + ")  ");
            int rows = DbHelperMySQL.ExecuteSql(strSql.ToString());
            if (rows > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }


        /// <summary>
        /// 得到一个对象实体
        /// </summary>
        public DataServer.Model.electricity_data GetModel(string ElectricityId)
        {

            StringBuilder strSql = new StringBuilder();
            strSql.Append("select ElectricityId,DeviceId,EH,P,Kvar,Ia,Ib,Ic,Ua,Ub,Uc,ServiceRating,CreateTime,EntireTime,Reserve1,Reserve2,Reserve3,Reserve4,Reserve5 from electricity_data ");
            strSql.Append(" where ElectricityId=@ElectricityId ");
            MySqlParameter[] parameters = {
                    new MySqlParameter("@ElectricityId", MySqlDbType.VarChar,255)           };
            parameters[0].Value = ElectricityId;

            DataServer.Model.electricity_data model = new DataServer.Model.electricity_data();
            DataSet ds = DbHelperMySQL.Query(strSql.ToString(), parameters);
            if (ds.Tables[0].Rows.Count > 0)
            {
                return DataRowToModel(ds.Tables[0].Rows[0]);
            }
            else
            {
                return null;
            }
        }


        /// <summary>
        /// 得到一个对象实体
        /// </summary>
        public DataServer.Model.electricity_data DataRowToModel(DataRow row)
        {
            DataServer.Model.electricity_data model = new DataServer.Model.electricity_data();
            if (row != null)
            {
                if (row["ElectricityId"] != null)
                {
                    model.ElectricityId = row["ElectricityId"].ToString();
                }
                if (row["DeviceId"] != null)
                {
                    model.DeviceId = row["DeviceId"].ToString();
                }
                if (row["EH"] != null && row["EH"].ToString() != "")
                {
                    model.EH = decimal.Parse(row["EH"].ToString());
                }
                if (row["P"] != null && row["P"].ToString() != "")
                {
                    model.P = decimal.Parse(row["P"].ToString());
                }
                if (row["Kvar"] != null && row["Kvar"].ToString() != "")
                {
                    model.Kvar = decimal.Parse(row["Kvar"].ToString());
                }
                if (row["Ia"] != null && row["Ia"].ToString() != "")
                {
                    model.Ia = decimal.Parse(row["Ia"].ToString());
                }
                if (row["Ib"] != null && row["Ib"].ToString() != "")
                {
                    model.Ib = decimal.Parse(row["Ib"].ToString());
                }
                if (row["Ic"] != null && row["Ic"].ToString() != "")
                {
                    model.Ic = decimal.Parse(row["Ic"].ToString());
                }
                if (row["Ua"] != null && row["Ua"].ToString() != "")
                {
                    model.Ua = decimal.Parse(row["Ua"].ToString());
                }
                if (row["Ub"] != null && row["Ub"].ToString() != "")
                {
                    model.Ub = decimal.Parse(row["Ub"].ToString());
                }
                if (row["Uc"] != null && row["Uc"].ToString() != "")
                {
                    model.Uc = decimal.Parse(row["Uc"].ToString());
                }
                if (row["ServiceRating"] != null && row["ServiceRating"].ToString() != "")
                {
                    model.ServiceRating = decimal.Parse(row["ServiceRating"].ToString());
                }
                if (row["CreateTime"] != null && row["CreateTime"].ToString() != "")
                {
                    model.CreateTime = DateTime.Parse(row["CreateTime"].ToString());
                }
                if (row["EntireTime"] != null && row["EntireTime"].ToString() != "")
                {
                    model.EntireTime = DateTime.Parse(row["EntireTime"].ToString());
                }
                if (row["Reserve1"] != null)
                {
                    model.Reserve1 = row["Reserve1"].ToString();
                }
                if (row["Reserve2"] != null)
                {
                    model.Reserve2 = row["Reserve2"].ToString();
                }
                if (row["Reserve3"] != null)
                {
                    model.Reserve3 = row["Reserve3"].ToString();
                }
                if (row["Reserve4"] != null)
                {
                    model.Reserve4 = row["Reserve4"].ToString();
                }
                if (row["Reserve5"] != null)
                {
                    model.Reserve5 = row["Reserve5"].ToString();
                }
            }
            return model;
        }

        /// <summary>
        /// 获得数据列表
        /// </summary>
        public DataSet GetList(string strWhere)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("select ElectricityId,DeviceId,EH,P,Kvar,Ia,Ib,Ic,Ua,Ub,Uc,ServiceRating,CreateTime,EntireTime,Reserve1,Reserve2,Reserve3,Reserve4,Reserve5 ");
            strSql.Append(" FROM electricity_data ");
            if (strWhere.Trim() != "")
            {
                strSql.Append(" where " + strWhere);
            }
            return DbHelperMySQL.Query(strSql.ToString());
        }

        /// <summary>
        /// 获取记录总数
        /// </summary>
        public int GetRecordCount(string strWhere)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("select count(1) FROM electricity_data ");
            if (strWhere.Trim() != "")
            {
                strSql.Append(" where " + strWhere);
            }
            object obj = DbHelperSQL.GetSingle(strSql.ToString());
            if (obj == null)
            {
                return 0;
            }
            else
            {
                return Convert.ToInt32(obj);
            }
        }
        /// <summary>
        /// 分页获取数据列表
        /// </summary>
        public DataSet GetListByPage(string strWhere, string orderby, int startIndex, int endIndex)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("SELECT * FROM ( ");
            strSql.Append(" SELECT ROW_NUMBER() OVER (");
            if (!string.IsNullOrEmpty(orderby.Trim()))
            {
                strSql.Append("order by T." + orderby);
            }
            else
            {
                strSql.Append("order by T.ElectricityId desc");
            }
            strSql.Append(")AS Row, T.*  from electricity_data T ");
            if (!string.IsNullOrEmpty(strWhere.Trim()))
            {
                strSql.Append(" WHERE " + strWhere);
            }
            strSql.Append(" ) TT");
            strSql.AppendFormat(" WHERE TT.Row between {0} and {1}", startIndex, endIndex);
            return DbHelperMySQL.Query(strSql.ToString());
        }

        /*
		/// <summary>
		/// 分页获取数据列表
		/// </summary>
		public DataSet GetList(int PageSize,int PageIndex,string strWhere)
		{
			MySqlParameter[] parameters = {
					new MySqlParameter("@tblName", MySqlDbType.VarChar, 255),
					new MySqlParameter("@fldName", MySqlDbType.VarChar, 255),
					new MySqlParameter("@PageSize", MySqlDbType.Int32),
					new MySqlParameter("@PageIndex", MySqlDbType.Int32),
					new MySqlParameter("@IsReCount", MySqlDbType.Bit),
					new MySqlParameter("@OrderType", MySqlDbType.Bit),
					new MySqlParameter("@strWhere", MySqlDbType.VarChar,1000),
					};
			parameters[0].Value = "electricity_data";
			parameters[1].Value = "ElectricityId";
			parameters[2].Value = PageSize;
			parameters[3].Value = PageIndex;
			parameters[4].Value = 0;
			parameters[5].Value = 0;
			parameters[6].Value = strWhere;	
			return DbHelperMySQL.RunProcedure("UP_GetRecordByPage",parameters,"ds");
		}*/

        #endregion  BasicMethod
        #region  ExtensionMethod
        /// <summary>
        /// 表是否存在
        /// </summary>
        /// <param name="dbName">数据库名</param>
        /// <param name="tableName">表名 格式：表名_yyyyMMdd</param>
        /// <returns></returns>
        public bool IsExistsTable(string dbName, string tableName)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append(string.Format("select count(1) from information_schema.tables where table_schema='{0}'  and table_name='{1}' ", dbName, tableName));
            return DbHelperMySQL.Exists(strSql.ToString());
        }

        /// <summary>
        /// 添加表
        /// </summary>
        /// <param name="date">日期 格式：yyyyMM</param>
        /// <returns></returns>
        public void CreateTable(string date)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("CREATE TABLE `electricity_data_" + date + "` (");
            strSql.Append("`ElectricityId` varchar(255) NOT NULL COMMENT '用电Id',");
            strSql.Append("`DeviceId` varchar(255) DEFAULT NULL COMMENT '设备Id',");
            strSql.Append("`EH` float(255,3) DEFAULT NULL COMMENT '用电量',");
            strSql.Append("`P` float(255,3) DEFAULT NULL COMMENT '实时负荷',");
            strSql.Append("`Kvar` float(255,3) DEFAULT NULL COMMENT '总无工功率',");
            strSql.Append("`Ia` float(255,3) DEFAULT NULL COMMENT 'A相电流',");
            strSql.Append("`Ib` float(255,3) DEFAULT NULL COMMENT 'B相电流',");
            strSql.Append("`Ic` float(255,3) DEFAULT NULL COMMENT 'C相电流',");
            strSql.Append("`Ua` float(255,3) DEFAULT NULL COMMENT 'A相电压',");
            strSql.Append("`Ub` float(255,3) DEFAULT NULL COMMENT 'B相电压',");
            strSql.Append("`Uc` float(255,3) DEFAULT NULL COMMENT 'C相电压',");
            strSql.Append("`ServiceRating` float(255,3) DEFAULT NULL COMMENT '运行功率',");
            strSql.Append("`CreateTime` datetime DEFAULT NULL COMMENT '添加时间',");
            strSql.Append("`EntireTime` datetime DEFAULT NULL COMMENT '整点时间',");
            strSql.Append("`Reserve1` varchar(255) DEFAULT NULL,");
            strSql.Append("`Reserve2` varchar(255) DEFAULT NULL,");
            strSql.Append("`Reserve3` varchar(255) DEFAULT NULL,");
            strSql.Append("`Reserve4` varchar(255) DEFAULT NULL,");
            strSql.Append("`Reserve5` varchar(255) DEFAULT NULL,");
            strSql.Append("PRIMARY KEY (`ElectricityId`)");
            strSql.Append(") ENGINE=InnoDB DEFAULT CHARSET=utf8;");
            DbHelperMySQL.ExecuteSql(strSql.ToString());
        }

        /// <summary>
        ///添加数据
        /// </summary>
        /// <param name="model"></param>
        /// <param name="date"></param>
        /// <returns></returns>
        public bool AddDate(DataServer.Model.electricity_data model, string date)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("insert into electricity_data_" + date + "(");
            strSql.Append("ElectricityId,DeviceId,EH,P,Kvar,Ia,Ib,Ic,Ua,Ub,Uc,ServiceRating,CreateTime,EntireTime,Reserve1,Reserve2,Reserve3,Reserve4,Reserve5)");
            strSql.Append(" values (");
            strSql.Append("@ElectricityId,@DeviceId,@EH,@P,@Kvar,@Ia,@Ib,@Ic,@Ua,@Ub,@Uc,@ServiceRating,@CreateTime,@EntireTime,@Reserve1,@Reserve2,@Reserve3,@Reserve4,@Reserve5)");
            MySqlParameter[] parameters = {
                    new MySqlParameter("@ElectricityId", MySqlDbType.VarChar,255),
                    new MySqlParameter("@DeviceId", MySqlDbType.VarChar,255),
                    new MySqlParameter("@EH", MySqlDbType.Float,255),
                    new MySqlParameter("@P", MySqlDbType.Float,255),
                    new MySqlParameter("@Kvar", MySqlDbType.Float,255),
                    new MySqlParameter("@Ia", MySqlDbType.Float,255),
                    new MySqlParameter("@Ib", MySqlDbType.Float,255),
                    new MySqlParameter("@Ic", MySqlDbType.Float,255),
                    new MySqlParameter("@Ua", MySqlDbType.Float,255),
                    new MySqlParameter("@Ub", MySqlDbType.Float,255),
                    new MySqlParameter("@Uc", MySqlDbType.Float,255),
                    new MySqlParameter("@ServiceRating", MySqlDbType.Float,255),
                    new MySqlParameter("@CreateTime", MySqlDbType.DateTime),
                    new MySqlParameter("@EntireTime", MySqlDbType.DateTime),
                    new MySqlParameter("@Reserve1", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve2", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve3", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve4", MySqlDbType.VarChar,255),
                    new MySqlParameter("@Reserve5", MySqlDbType.VarChar,255)};
            parameters[0].Value = model.ElectricityId;
            parameters[1].Value = model.DeviceId;
            parameters[2].Value = model.EH;
            parameters[3].Value = model.P;
            parameters[4].Value = model.Kvar;
            parameters[5].Value = model.Ia;
            parameters[6].Value = model.Ib;
            parameters[7].Value = model.Ic;
            parameters[8].Value = model.Ua;
            parameters[9].Value = model.Ub;
            parameters[10].Value = model.Uc;
            parameters[11].Value = model.ServiceRating;
            parameters[12].Value = model.CreateTime;
            parameters[13].Value = model.EntireTime;
            parameters[14].Value = model.Reserve1;
            parameters[15].Value = model.Reserve2;
            parameters[16].Value = model.Reserve3;
            parameters[17].Value = model.Reserve4;
            parameters[18].Value = model.Reserve5;

            int rows = DbHelperMySQL.ExecuteSql(strSql.ToString(), parameters);
            if (rows > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        /// <summary>
        /// 获得数据列表
        /// </summary>
        public DataSet GetListDate(string strWhere, string date)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("select ElectricityId,DeviceId,EH,P,Kvar,Ia,Ib,Ic,Ua,Ub,Uc,ServiceRating,CreateTime,EntireTime,Reserve1,Reserve2,Reserve3,Reserve4,Reserve5 ");
            strSql.Append(" FROM electricity_data_" + date);
            if (strWhere.Trim() != "")
            {
                strSql.Append(" where " + strWhere);
            }
            return DbHelperMySQL.Query(strSql.ToString());
        }

        /// <summary>
		/// 获取数据
		/// </summary>
		/// <param name="source">数据来源</param>
		/// <param name="strWhere">条件</param>
		/// <param name="timeField">时间字段</param>
		/// <returns></returns>
		public DataSet GetList(string source, string strWhere, string timeField)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("SELECT * FROM (" + source + ") as T ");
            if (strWhere.Trim() != "")
            {
                strSql.Append(" where " + strWhere);
            }
            if (!string.IsNullOrEmpty(timeField))
            {
                strSql.Append("ORDER BY " + timeField + " ");
            }
            return DbHelperMySQL.Query(strSql.ToString(), 300);
        }

        /// <summary>
		/// 获取数据
		/// </summary>
		/// <param name="source">数据来源</param>
		/// <param name="strWhere">条件</param>
		/// <param name="sum_name">求和字段</param>
		/// <returns></returns>
		public decimal GetSum(string source, string strWhere, string sum_name)
        {
            StringBuilder strSql = new StringBuilder();
            strSql.Append("SELECT sum(" + sum_name + ") FROM (" + source + ") as T ");
            if (strWhere.Trim() != "")
            {
                strSql.Append(" where " + strWhere);
            }
            object obj = DbHelperSQL.GetSingle(strSql.ToString(), 300);
            if (obj == null)
            {
                return 0;
            }
            else
            {
                return Convert.ToDecimal(obj);
            }
        }
        #endregion  ExtensionMethod
    }
}