Question

我的MasterSales表看起来像这样

SalesDate | Category | Total
----------------------------- 
1/1/2000    01          100 
1/1/2000    02          110
1/2/2000    01          80
1/2/2000    03          20

我的Category表看起来像这样

ID | Name
----------
01 | A
02 | B
03 | C
04 | D

我的查询如下：

SELECT m.SalesDate, c.Name, SUM(ISNULL(m.Total,0)) AS TotalSales
FROM MasterSales m
LEFT JOIN Category c ON c.ID = m.Category
WHERE m.SalesDate BETWEEN '1/1/2000' AND '1/2/2000'

我想要的结果是这样的：

SalesDate | Name | TotalSales
------------------------------
1/1/2000    A      100
1/1/2000    B      110
1/1/2000    C      0
1/1/2000    D      0
1/2/2000    A      80
1/2/2000    B      0
1/2/2000    C      20
1/2/2000    D      0

但我得到的结果看起来是这样的：

SalesDate | Name | TotalSales
------------------------------
1/1/2000    A      100
1/1/2000    B      110
1/2/2000    A      80
1/2/2000    C      20

我已尝试使用RIGHT JOIN代替LEFT JOIN并在FROM子句上切换表格，但结果仍然相同。任何人都可以帮我解释为什么它不能正常工作？

P.S。：我正在使用SQL Server 2005（如果重要）

Answer 1

试试这个。这包括您拥有 MasterSales 的所有日期。换句话说，这填补了当天缺失的类别。但是，您也希望填写缺少的日期，您需要创建日期控制表..查看 recursive cte 了解日期表

;with control_table as (
  select distinct SalesDate, ID
  from MasterSales ms
  cross join Category c
  where ms.SalesDate between '1/1/2000' AND '1/2/2000'
  )


select ct.SalesDate, c.Name as Category, coalesce(sum(ms.Total),0) as Total
from control_table ct
inner join Category c
  on ct.ID = c.ID
left join MasterSales ms
  on ct.SalesDate = ms.SalesDate
  and ct.ID = ms.Category
group by ct.SalesDate, c.Name
order by ct.SalesDate asc, c.Name asc

<强> FIDDLE

Answer 2

这是我的回答

WITH MasterSales (SalesDate, Category, Total) AS (
  SELECT       '1/1/2000','01',100
  UNION SELECT '1/1/2000','02',110
  UNION SELECT '1/2/2000','01',80
  UNION SELECT '1/2/2000','03',20
), Category (ID, Name) AS (
  SELECT       '01','A'
  UNION SELECT '02','B'
  UNION SELECT '03','C'
  UNION SELECT '04','D'
), getDates AS (
  SELECT DISTINCT SalesDate 
  FROM MasterSales 
  WHERE SalesDate BETWEEN '1/1/2000' AND '1/2/2000'
)

SELECT gD.SalesDate, C.Name, SUM(ISNULL(MS.Total,0)) AS TotalSales
FROM getDates AS gD
CROSS JOIN Category AS C
LEFT JOIN MasterSales AS MS 
    ON MS.Category = C.ID
    AND MS.SalesDate = gD.SalesDate 
GROUP BY gD.SalesDate, C.Name

Answer 3

最后，你的问题解决了。使用此查询：

SELECT AAA.SalesDate,AAA.Name,ISNULL(BBB.TotalSales,0) as TotalSales  
FROM (
    (SELECT m.SalesDate, c.Name
    FROM MasterSales m,Category c
    WHERE m.SalesDate BETWEEN '1/1/2000' AND '1/2/2000'
    GROUP BY m.SalesDate,c.Name) AAA

    LEFT JOIN 

    (SELECT m.SalesDate,c.Name, SUM(ISNULL(m.Total,0)) AS TotalSales
    FROM MasterSales m,Category c
    WHERE m.SalesDate BETWEEN '1/1/2000' AND '1/2/2000'
    AND c.ID=m.Category 
    GROUP BY m.SalesDate,c.Name) BBB 
    on AAA.SalesDate=BBB.SalesDate AND AAA.Name=BBB.Name)

<强>解释

查询的第一部分（AAA）选择SalesDate和Category的所有组合。

查询的第二部分（BBB）选择SalesDate，Category和TotalSales。

然后我们在SalesDate和Category加入他们（AAA和BBB）。

完美的工作!!!请参阅SQL Fiddle。

Answer 4

更新：更改了使用sam yi logic创建临时表的方法

我建议你创建一个附加表。

;WITH control_table AS (
      SELECT DISTINCT SalesDate, Name
        FROM MasterSales ms
             CROSS JOIN Category c
       )

SELECT d.SalesDate,
       c.name,
       COALESCE(sum(m.total),0) totalsales
  FROM control_table d
       LEFT OUTER JOIN Category c
            ON d.Name = c.name
       LEFT OUTER JOIN MasterSales m
            ON (c.id = m.category
                AND d.SalesDate = m.salesdate)
WHERE d.SalesDate BETWEEN '1/1/2000' 
                      AND '1/2/2000'
GROUP BY 
       d.SalesDate,
       c.name
ORDER BY 
       d.SalesDate,
       c.name;

Here is SQLFiddle

Answer 5

SELECT cj.Date, cj.Name, IsNull(m.Total,0) Total
FROM (SELECT d.Date, c.Name, c.Id
    FROM (SELECT DISTINCT SalesDate Date 
          FROM MasterSales) d, Category c) cj
LEFT JOIN MasterSales m ON m.SalesDate = cj.Date 
  AND cj.Id = m.Category

http://www.sqlfiddle.com/#!3/d1344/3

添加日期条件

我确信有更好的方法可以做到这一点。

干杯

为什么这个查询不能正常工作？

5 个答案: