Question

我有两张桌子。

包含客户和日期的订单表。来自数据仓库的日期维度表。

订单表不包含给定月份中每个日期的活动，但我需要返回填充日期和客户的差距的结果集。

例如，我需要这个：

Customer   Date
===============================
Cust1       1/15/2012   
Cust1       1/18/2012
Cust2       1/5/2012
Cust2       1/8/2012

看起来像这样：

Customer   Date
============================
Cust1       1/15/2012   
Cust1       1/16/2012   
Cust1       1/17/2012       
Cust1       1/18/2012
Cust2       1/5/2012
Cust2       1/6/2012
Cust2       1/7/2012
Cust2       1/8/2012

这似乎是左外连接，但它没有返回预期的结果。这是我正在使用的，但这并不是按预期返回日期表中的每个日期。

SELECT o.customer, 
       d.fulldate
FROM   datetable d 
       LEFT OUTER JOIN orders o 
                    ON d.fulldate = o.orderdate 
WHERE  d.calendaryear IN ( 2012 );

Answer 1

您可以使用递归CTE获取两个日期之间的所有日期，而无需datetable：

;WITH CTE_MinMax AS
(
    SELECT Customer, MIN(DATE) AS MinDate, MAX(DATE) AS MaxDate
    FROM dbo.orders
    GROUP BY Customer
)
,CTE_Dates AS
(
    SELECT Customer, MinDate AS Date
    FROM CTE_MinMax
    UNION ALL
    SELECT c.Customer, DATEADD(DD,1,Date) FROM CTE_Dates c
    INNER JOIN CTE_MinMax mm ON c.Customer = mm.Customer
    WHERE DATEADD(DD,1,Date) <= mm.MaxDate
)
SELECT c.* , COALESCE(o.Amount, 0)
FROM CTE_Dates c
LEFT JOIN Orders o ON c.Customer = o.Customer AND c.Date = o.Date
ORDER BY Customer, Date
OPTION (MAXRECURSION 0)

<强> SQLFiddle DEMO

Answer 2

问题是您需要所有日期的所有客户。当您执行left outer join时，您将获得客户字段的NULL。

以下按cross join客户名称和日期设置驱动程序表：

SELECT driver.customer, driver.fulldate, o.amount 
FROM   (select d.fulldate, customer
        from datetable d cross join
             (select customer
              from orders
              where year(orderdate) in (2012)
             ) o
        where d.calendaryear IN ( 2012 )
       ) driver LEFT OUTER JOIN
       orders o 
       ON driver.fulldate = o.orderdate and
          driver.customer = o.customer;

请注意，此版本假定calendaryear与year(orderdate)相同。

Answer 3

这是一种简单的方法：

SELECT  A.Customer,
        B.fulldate [Date],
        ISNULL(C.Amount,0) Amount
FROM (  SELECT  Customer, 
                MIN([Date]) MinDate,
                MAX([Date]) MaxDate
        FROM Orders
        GROUP BY Customer) A
LEFT JOIN DateTable B
    ON B.fulldate BETWEEN A.MinDate AND A.MaxDate
LEFT JOIN Orders C
    ON A.Customer = C.Customer 
    AND B.fulldate = C.[Date]

Answer 4

假设日期表包含一年中的每个日期，您可以使用一个简单的CTE

WITH OrdersCustomerDateBorders AS
(
    SELECT CustomerID, MIN(fulldate) AS FirstOrderDate, MAX(fulldate) AS LastOrderDate
    FROM orders
    GROUP BY customer
)
select o.customer, d.fulldate, ISNULL(o.amount, 0) AS Amount
from orders o
INNER JOIN OrdersCustomerDateBorders OCDB ON OCDB.CustomerID = o.CustomerID
INNER JOIN datetable d ON  ON d.fulldate between OCDB.FirstOrderDate AND OCDB.LastOrderDate
WHERE d.calendaryear in (2012);

用日期表填写日期差距

4 个答案: