PIVOT / UNPIVOT

Question

我有两个表，一个表的状态-这是一个不断变化的列表-因此下周可以添加一个值，例如4 |递延：

ID | Status
1  | Open
2  | Closed
3  | Pending

其他带有任务的

ID | Name   | Status ID
1  | Task A | 1
2  | Task B | 1
3  | Task A | 2
4  | Task A | 3
5  | Task C | 2

我想输出每个潜在状态下每个任务（类型）的总和：

Task   | Open | Closed | Pending
Task A | 1    | 1      | 1
Task B | 1    | 0      | 0
Task C | 0    | 1      | 0

我相信PIVOT可以将动态行处理为列，但无法将动态less than dot example转换为我需要的内容。

Answer 1

您可以进行有条件的聚合：

select t.name, 
       sum(case when s.Status = 'Open' then 1 else 0 end) as Open,
       sum(case when s.Status = 'Closed' then 1 else 0 end) as Closed,
       sum(case when s.Status = 'Pending' then 1 else 0 end) as Pending
from status s left join
     tasks t
     on t.StatusID = s.id
group by t.name;

Answer 2

请参考此查询[] []

SELECT t2.name
        ,max(CASE 
                WHEN t2.statID = 1
                    THEN 1
                ELSE 0
                END) AS

    OPEN
        ,max(CASE 
                WHEN t2.statID = 2
                    THEN 1
                ELSE 0
                END) AS Closed
        ,max(CASE 
                WHEN t2.statID = 3
                    THEN 1
                ELSE 0
                END) AS pending
    FROM t2
    INNER JOIN t1 ON t1.INT = t2.statID
    GROUP BY t2.name

Answer 3

要管理新状态，可以使用动态TSQL：

create table #status([ID] int, [Status] varchar(max))

 insert into #status values
 (1  ,'Open')
,(2  ,'Closed')
,(3  ,'Pending')

create table #task([ID] int, [Name] varchar(max), StatusID int)

insert into #task values
 (1, 'Task A', 1)
,(2, 'Task B', 1)
,(3, 'Task A', 2)
,(4, 'Task A', 3)
,(5, 'Task C', 2)


declare @sql nvarchar(max)='select t.name as [Name]  ' 
select @sql = @sql + ', sum(case when s.Status = ''' + [Status] + ''' then 1 else 0 end) as [' + [Status] + ' ] '

from #status

select @sql = @sql + ' from #status s left join'
select @sql = @sql + '      #task t'
select @sql = @sql + '      on t.StatusID = s.id'
select @sql = @sql + ' group by t.name;'

execute(@sql)

数据结果：

再添加2个状态（Status4和Status5）：

create table #status([ID] int, [Status] varchar(max))

 insert into #status values
 (1  ,'Open')
,(2  ,'Closed')
,(3  ,'Pending')
,(4  ,'Status4')
,(5  ,'Status5')

create table #task([ID] int, [Name] varchar(max), StatusID int)

insert into #task values
 (1, 'Task A', 1)
,(2, 'Task B', 1)
,(3, 'Task A', 2)
,(4, 'Task A', 3)
,(5, 'Task C', 2)
,(6, 'Task D', 4)
,(7, 'Task D', 5)


declare @sql nvarchar(max)='select t.name as [Name]  ' 
select @sql = @sql + ', sum(case when s.Status = ''' + [Status] + ''' then 1 else 0 end) as [' + [Status] + ' ] '

from #status

select @sql = @sql + ' from #status s left join'
select @sql = @sql + '      #task t'
select @sql = @sql + '      on t.StatusID = s.id'
select @sql = @sql + ' group by t.name;'

execute(@sql)

结果：

Answer 4

使用数据透视尝试

DECLARE @Table AS TABLE(ID INT, Status VARCHAR(10))
INSERT INTO @Table
SELECT 1,'Open'     UNION ALL
SELECT 2,'Closed'   UNION ALL
SELECT 3,'Pending'

DECLARE @Table2 AS TABLE(ID INT, Name  VARCHAR(10), StatusID VARCHAR(10))
INSERT INTO @Table2

SELECT 1,'Task A',1 UNION ALL
SELECT 2,'Task B',1 UNION ALL
SELECT 3,'Task A',2 UNION ALL
SELECT 4,'Task A',3 UNION ALL
SELECT 5,'Task C',2

;WITH CTE
AS
(
SELECT T1.Name, 
        T1.StatusID,
        t2.[Status] 
FROM @Table2 T1
INNER JOIN @Table T2
 ON t1.StatusID=T2.ID
)
SELECT Name,
       [Open],
       [Closed],
       [Pending]
FROM
(
SELECT * FROM CTE
)AS Src
PIVOT
(
COUNT(StatusID) FOR [Status] IN ([Open],[Closed],[Pending])
) AS PVT

结果

Name    Open Closed Pending
------------------------------
TaskA    1     1         1
TaskB    1     0         0
TaskC    0     1         0

Answer 5

@lojkyelo-这应该为您提供所需的逻辑。基本上，您将需要一个具有从状态表中提取的动态列的数据透视表。然后，将使用动态查询传递@PivotColumn。

在http://rextester.com/FSN2383处查看模型并在下面查询：

CREATE TABLE  #Status ([ID] int, [Status] varchar(max))

INSERT INTO #Status 
SELECT 1,'Open' UNION ALL
SELECT 2,'Closed' UNION ALL
SELECT 3,'Pending' UNION ALL
SELECT 4,'Deferred' 

CREATE TABLE  #Task ([ID] int, [Name] varchar(max), StatusID int)
INSERT INTO #Task 
SELECT 1, 'Task A', 1 UNION ALL
SELECT 2, 'Task B', 1 UNION ALL
SELECT 3, 'Task A', 2 UNION ALL
SELECT 4, 'Task A', 3 UNION ALL
SELECT 5, 'Task C', 2 UNION ALL
SELECT 6, 'Task C', 4 



DECLARE @columns NVARCHAR(MAX), @sql NVARCHAR(MAX);
SET @columns = N'';
SELECT @columns += QUOTENAME(Status)+','
    FROM (SELECT p.Status FROM #Status p group by p.Status
    ) AS x;


DECLARE @Pivotcolumns NVARCHAR(MAX)=(select  left (@columns, Len ( @columns) - 1 ))

DECLARE @query NVARCHAR(MAX) = '
      SELECT *
      FROM
      (
            SELECT 
                s.Status,t.Name,StatusID=sum(t.StatusID)
            FROM #Status S
            LEFT JOIN #Task T ON 
                t.StatusID = s.id
            GROUP BY
            s.Status,t.Name

      ) x1
      PIVOT
      (
        COUNT(StatusID)
        for [Status] in ('+ @Pivotcolumns +')
      ) p'

EXEC(@query)