Question

我设置了以下表格：

   CREATE TABLE app_detail
(
CustID1 int,
CustID2 int,
AppDate datetime
)

CREATE TABLE inv_detail
(
CustID1 int,
CustID2 int,
PostDate datetime,
ClearDate datetime,
Amt float
)

INSERT INTO app_detail
VALUES(583,246,'2013-04-30 00:00:00.000')
INSERT INTO app_detail
VALUES(583,246,'2015-06-17 00:00:00.000')

INSERT INTO inv_detail
VALUES(583,246,'2013-04-05 00:00:00.000',NULL,17.56)
INSERT INTO inv_detail
VALUES(583,246,'2013-04-05 00:00:00.000','2013-12-31 00:00:00.000',667.97)
INSERT INTO inv_detail
VALUES(583,246,'2013-04-05 00:00:00.000','2014-10-05 00:00:00.000',3.96)
INSERT INTO inv_detail
VALUES(583,246,'2013-04-05 00:00:00.000',NULL,48.40)
INSERT INTO inv_detail
VALUES(583,246,'2013-01-08 00:00:00.000','2013-12-31 00:00:00.000',332.03)
INSERT INTO inv_detail
VALUES(583,246,'2013-01-08 00:00:00.000','2013-12-31 00:00:00.000',63.10)


INSERT INTO inv_detail
VALUES(583,246,'2013-07-09 00:00:00.000',NULL,1062.29)
INSERT INTO inv_detail
VALUES(583,246,'2013-04-05 00:00:00.000',NULL,17.56)
INSERT INTO inv_detail
VALUES(583,246,'2013-04-05 00:00:00.000',NULL,48.40)

select * from app_detail
select * from inv_detail

我想得到以下输出：

SELECT
 '583' AS CustID1
,'246' AS CustID2
,'2013-04-30 00:00:00.000' AS AppDate
,'1133.02' AS TotalAmount

UNION
SELECT
 '583'
,'246'
,'2015-06-17 00:00:00.000'
,'1128.25'

CustID1 CustID2 AppDate    TotalAmount
583      246    2013-04-30  1133.02
583      246    2015-06-17  1128.25

第一个表包含有关在特定日期创建应用程序的客户的数据。第二个表格包含这些客户的发票详细信息，发票发送时间和付款（清算）时间。我想知道客户在申请日期尚未结清的发票金额。如果已支付发票，则ClearedDate列中将有一个日期。如果从未支付发票，则它将为NULL。

我想到的唯一方法是通过一个循环，我一次只将一个AppDate传递给WHERE子句。但是我希望我可以取消它。

任何帮助都将不胜感激。

Answer 1

您可以使用outer apply而不是手动循环执行此操作：

select a.*, due.Total
from app_detail a
outer apply (
    select sum(Amt) [Total]
    from inv_detail i
    where 
        i.CustID1=a.CustID1 and i.CustID2=a.CustID2 and 
        i.PostDate <= a.AppDate and (i.ClearDate is null or i.ClearDate > a.AppDate)
) due

在我从测试数据中删除了两个重复的行后，它返回了正确的结果（17.56和48.40都有两个条目。）

这不是一种特别有效的方法 - 它会导致inv_detail中每行app_detail的表扫描（或可能是索引扫描，如果有适当的索引）。但是，在这种情况下，我不相信有这种方法 - 它不是一个简单的聚合，因为来自inv_detail的一行可能涉及到许多行的计算app_detail。

Answer 2

借用Blorgbeard的回答来说明如何在没有子查询的情况下完成这项工作。

DECLARE @app_detail TABLE (CustID1 int,CustID2 int,AppDate datetime)
DECLARE @inv_detail TABLE(CustID1 int,CustID2 int,PostDate datetime,ClearDate datetime,Amt float)

INSERT INTO @app_detail VALUES(583,246,'2013-04-30 00:00:00.000')
INSERT INTO @app_detail VALUES(583,246,'2015-06-17 00:00:00.000')

INSERT INTO @inv_detail VALUES(583,246,'2013-04-05 00:00:00.000',NULL,17.56)
INSERT INTO @inv_detail VALUES(583,246,'2013-04-05 00:00:00.000','2013-12-31 00:00:00.000',667.97)
INSERT INTO @inv_detail VALUES(583,246,'2013-04-05 00:00:00.000','2014-10-05 00:00:00.000',3.96)
INSERT INTO @inv_detail VALUES(583,246,'2013-04-05 00:00:00.000',NULL,48.40)
INSERT INTO @inv_detail VALUES(583,246,'2013-01-08 00:00:00.000','2013-12-31 00:00:00.000',332.03)
INSERT INTO @inv_detail VALUES(583,246,'2013-01-08 00:00:00.000','2013-12-31 00:00:00.000',63.10)
INSERT INTO @inv_detail VALUES(583,246,'2013-07-09 00:00:00.000',NULL,1062.29)
INSERT INTO @inv_detail VALUES(583,246,'2013-04-05 00:00:00.000',NULL,17.56)
INSERT INTO @inv_detail VALUES(583,246,'2013-04-05 00:00:00.000',NULL,48.40)

select a.*, sum(Amt) AS [Total]
from @app_detail a
LEFT JOIN @inv_detail i ON i.CustID1=a.CustID1
    AND i.CustID2=a.CustID2
    AND i.PostDate <= a.AppDate
    AND (i.ClearDate is null or i.ClearDate > a.AppDate)
GROUP BY a.CustID1,a.CustID2,a.AppDate

替换循环查询

2 个答案: