陈优章的专栏
(原创，到现在为至最为复杂的SQL查询代码）实现按部门月卡余额总额分组统计的SQL查询代码（在Ms SQL Server中调试通过)
SELECT dp.dpname1 AS 部门, cust_dp_SumOddfre.sum_oddfare AS 当月卡总余额FROM (SELECT T_Department.DpCode1, SUM(custid_SumOddfare_group.sum_oddfare) AS sum_oddfare FROM (SELECT l2.CustomerID, SUM(r1.oddfare) AS sum_oddfare FROM (SELECT CustomerID, MAX(OpCount) AS max_opcount FROM (SELECT CustomerID, OpCount, RTRIM(CAST(YEAR(OpDt) AS char)) + '-' + RTRIM(CAST(MONTH(OpDt) AS char)) + '-' + RTRIM(DAY(0)) AS dt FROM T_ConsumeRec UNION SELECT CustomerID, OpCount, RTRIM(CAST(YEAR(cashDt) AS char)) + '-' + RTRIM(CAST(MONTH(cashDt) AS char)) + '-' + RTRIM(DAY(0)) AS dt FROM T_Cashrec) l1 WHERE (dt <= '2005-6-1')/*输入查询月份,可用参数传递*/ GROUP BY CustomerID) l2 INNER JOIN (SELECT CustomerID, OpCount, oddfare FROM T_ConsumeRec UNION SELECT CustomerID, OpCount, oddfare FROM T_Cashrec) r1 ON l2.CustomerID = r1.CustomerID AND r1.OpCount = l2.max_opcount GROUP BY l2.CustomerID) custid_SumOddfare_group INNER JOIN T_Customers ON custid_SumOddfare_group.CustomerID = T_Customers.CustomerID INNER JOIN T_Department ON SUBSTRING(T_Customers.Account, 1, 2) = T_Department.DpCode1 AND SUBSTRING(T_Customers.Account, 3, 2) = T_Department.DpCode2 AND SUBSTRING(T_Customers.Account, 5, 3) = T_Department.DpCode3 GROUP BY DpCode1) cust_dp_SumOddfre INNER JOIN (SELECT DISTINCT dpcode1, dpname1 FROM t_department) dp ON dp.dpcode1 = cust_dp_SumOddfre.DpCode1
附：查询用到的基本表形成脚本：
CREATE TABLE [dbo].[T_CashRec] ( --出纳明细账本[StatID] [tinyint] NOT NULL ,[CashID] [smallint] NOT NULL ,[Port] [tinyint] NOT NULL ,[Term] [tinyint] NOT NULL ,[CashDt] [datetime] NOT NULL ,--存取款时间[CollectDt] [datetime] NOT NULL ,[CustomerID] [int] NOT NULL ,[OpCount] [int] NOT NULL ,--某卡的操作次数，只累加[InFare] [money] NOT NULL ,[OutFare] [money] NOT NULL ,[SumFare] [money] NOT NULL ,[OddFare] [money] NOT NULL ,--此次操作后该卡的余额[MngFare] [money] NOT NULL ,[Hz] [tinyint] NOT NULL ,[CurSum] [smallmoney] NULL ,[CurCount] [smallint] NULL ,[CardSN] [tinyint] NULL ) ON [PRIMARY]GO
CREATE TABLE [dbo].[T_ConsumeRec] ( --消费明细账本[StatID] [tinyint] NOT NULL ,[Port] [tinyint] NOT NULL ,[Term] [tinyint] NOT NULL ,[CustomerID] [int] NOT NULL ,[OpCount] [int] NOT NULL , --某卡的操作次数，只累加[OpDt] [datetime] NOT NULL ,--消费时间[CollectDt] [datetime] NOT NULL ,[MealID] [tinyint] NOT NULL ,[SumFare] [smallmoney] NOT NULL ,[OddFare] [smallmoney] NOT NULL ,--此次操作后该卡的余额[MngFare] [smallmoney] NOT NULL ,[OpFare] [smallmoney] NOT NULL ,[Hz] [tinyint] NOT NULL ,[MenuID] [smallint] NULL ,[MenuNum] [tinyint] NULL ,[OddFarePre] [smallmoney] NULL ,[RecNo] [smallint] NULL ,[CardSN] [tinyint] NOT NULL ,[CardVer] [tinyint] NULL ) ON [PRIMARY]GO
CREATE TABLE [dbo].[T_Customers] ( --客户账本[CustomerID] [int] NOT NULL , --客户号，主键[StatCode] [varchar] (3) COLLATE Chinese_PRC_CI_AS NOT NULL ,[Account] [varchar] (7) COLLATE Chinese_PRC_CI_AS NOT NULL ,--单位代号[Name] [varchar] (12) COLLATE Chinese_PRC_CI_AS NOT NULL ,[CardNo] [int] NOT NULL ,[CardSN] [tinyint] NULL ,[CardType] [tinyint] NOT NULL ,[Status] [tinyint] NOT NULL ,[OpenDt] [datetime] NOT NULL ,[CashID] [smallint] NOT NULL ,[SumFare] [smallmoney] NOT NULL ,[ConsumeFare] [smallmoney] NOT NULL ,[OddFare] [smallmoney] NOT NULL ,[OpCount] [int] NOT NULL ,[CurSubsidyFare] [smallmoney] NOT NULL ,[SubsidyDT] [datetime] NOT NULL ,[SubsidyOut] [char] (1) COLLATE Chinese_PRC_CI_AS NOT NULL ,[Alias] [varchar] (10) COLLATE Chinese_PRC_CI_AS NULL ,[outid] [varchar] (20) COLLATE Chinese_PRC_CI_AS NULL ,[UpdateID] [tinyint] NOT NULL ,[Pwd] [char] (4) COLLATE Chinese_PRC_CI_AS NULL ,[QuChargFare] [smallmoney] NULL ,[HasTaken] [tinyint] NULL ,[DragonCardNo] [char] (19) COLLATE Chinese_PRC_CI_AS NULL ,[ApplyCharg] [smallmoney] NULL ,[ChargPer] [smallmoney] NULL ,[MingZu] [varchar] (20) COLLATE Chinese_PRC_CI_AS NULL ,[Sex] [char] (2) COLLATE Chinese_PRC_CI_AS NULL ,[Memo] [varchar] (100) COLLATE Chinese_PRC_CI_AS NULL ,[WeiPeiDW] [varchar] (10) COLLATE Chinese_PRC_CI_AS NULL ,[CardConsumeType] [tinyint] NULL ,[LeaveSchoolDT] [datetime] NULL ,[UseValidDT] [tinyint] NOT NULL ,[NoUseDate] [datetime] NOT NULL ) ON [PRIMARY]GO
CREATE TABLE [dbo].[T_Department] ( --单位帐本,三级单位制,树型结构[DpCode1] [char] (2) COLLATE Chinese_PRC_CI_AS NOT NULL ,[DpCode2] [char] (2) COLLATE Chinese_PRC_CI_AS NULL ,[DpCode3] [char] (3) COLLATE Chinese_PRC_CI_AS NULL ,[DpName1] [varchar] (30) COLLATE Chinese_PRC_CI_AS NULL ,[DpName2] [varchar] (30) COLLATE Chinese_PRC_CI_AS NULL ,[DpName3] [varchar] (30) COLLATE Chinese_PRC_CI_AS NULL ,[N_SR] [int] NOT NULL ,[BatNum] [smallint] NULL ) ON [PRIMARY]GO
