SQL Pivot - 如何显示具有空值的所有行？答案

【问题标题】：SQL Pivot - How To Show all rows with null values?SQL Pivot - 如何显示具有空值的所有行？
【发布时间】：2017-01-03 14:40:09
【问题描述】：

有没有办法使用 Pivot 来包含具有空值的行？

理想情况下，我想要这样的输出

但是，目前 Pivot 没有返回空行，我得到这样的输出

我正在使用下面的代码来获取下面的结果集：

SELECT
    ID,
    Name,
    Design,
    month
FROM (SELECT
    E.EnrollId AS ID,
    E.EmployeeName AS Name,
    D.Designation AS
    Design,
    DATENAME(MONTH, La.Date) AS month,
    DATENAME(DAY, La.Date) AS Day,
    L.LeaveShortName AS Short
FROM Employee E
JOIN LeaveApplicationDates LA
    ON E.EnrollId = LA.EnrollId
JOIN Leave L
    ON L.LeaveId = LA.LeaveId
JOIN Designation D
    ON E.DesignationId = D.DesignationId
WHERE (E.EnrollId = '10277')
AND (La.Date BETWEEN '1/1/2016' AND '8/1/2016')) AS setr
PIVOT
(
MAX(Short)
FOR [Day] IN ([1], [2], [3], [4], [5], [6], [7], [8], [9], [10],
[11], [12], [13], [14], [15], [16], [17], [18], [19], [20],
[21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31])
) AS pivotTable

I follow this but solution not working

【问题讨论】：

在我看来，PIVOT 没有任何问题，但您的 SELECT；您需要先编写 SELECT 查询以输出所有月份
@techspider 怎么样？你想分享sn-p吗？我试过但搞砸了 sql 查询...

标签： sql sql-server join pivot row

【解决方案1】：

您可以使用 CTE 获取带有月份名称的表：

;WITH cte AS (
    SELECT  CAST('2016-01-01' as datetime) as d
    UNION ALL
    SELECT  DATEADD(month,1,d)
    FROM cte
    WHERE DATEPART(month,d) < 12
)

SELECT  DATEPART(month,d) as month_num,
        DATENAME(month,d) as month_name
FROM cte

输出：

month_num   month_name
1           January
2           February
3           March
4           April
5           May
6           June
7           July
8           August
9           September
10          October
11          November
12          December

并将其放入您的查询中，例如：

;WITH cte AS (
    SELECT  CAST('2016-01-01' as datetime) as d
    UNION ALL
    SELECT  DATEADD(month,1,d)
    FROM cte
    WHERE DATEPART(month,d) < 12
)

SELECT  ID,
        Name,
        Design,
        [month],
        [1], [2], [3], [4], [5], [6], [7], [8], [9], [10],
[11], [12], [13], [14], [15], [16], [17], [18], [19], [20],
[21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31]
FROM (
    SELECT  E.EnrollId AS ID,
            E.EmployeeName AS Name,
            D.Designation AS
            Design,
            month_num,
            month_name AS [month],
            DATENAME(DAY, La.[Date]) AS [Day],
            L.LeaveShortName AS Short
    FROM Employee E
    CROSS JOIN (
        SELECT  DATEPART(month,d) as month_num,
                DATENAME(month,d) as month_name
        FROM cte
        ) as mt
    LEFT JOIN LeaveApplicationDates LA
        ON E.EnrollId = LA.EnrollId and mt.month_name = DATENAME(MONTH, La.[Date]) and La.[Date] BETWEEN '1/1/2016' AND '8/1/2016'
    LEFT JOIN Leave L
        ON L.LeaveId = LA.LeaveId
    LEFT JOIN Designation D
        ON E.DesignationId = D.DesignationId
) AS setr
PIVOT
(
MAX(Short)
FOR [Day] IN ([1], [2], [3], [4], [5], [6], [7], [8], [9], [10],
[11], [12], [13], [14], [15], [16], [17], [18], [19], [20],
[21], [22], [23], [24], [25], [26], [27], [28], [29], [30], [31])
) AS pivotTable
WHERE ID = '10277'
ORDER BY ID, month_num

【讨论】：