是否可以按表中的元素进行分组（如中所示COLUMN LIKE='Value%'）PIVOT？我有一个表[DBT]。[Status]，其中包含各种状态（数据库，实例等），并且不想将所有PROD和TEST值作为单个值进行透视/查询，而是将它们分组。

例如代替具有用于状态列Prod，Prod ACC，Prod APP，...等。我将仅有一个包含的值列Name LIKE 'Prod%'和Name LIKE 'Test%'。

到目前为止，我有：

表定义

CREATE TABLE [DBT].[Status](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [Name] [nvarchar](50) NOT NULL,
 CONSTRAINT [PK_Status] PRIMARY KEY CLUSTERED 
(
    [ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 80) ON [PRIMARY],
 CONSTRAINT [IX_Status] UNIQUE NONCLUSTERED 
(
    [Name] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, FILLFACTOR = 80) ON [PRIMARY]
) ON [PRIMARY]

GO

表值

INSERT INTO [DBT].[Status]
(
    -- ID -- this column value is auto-generated
    Name
)
VALUES
('Test ACC'),
('Test APP'),
('Test DBA'),
('Prod ACC'),
('Prod APP'),
('Prod DBA'),
('Prod'),
('Test'),
('Migrated'),
('Offline'),
('Reserved')

透视状态表

SELECT 'Database Status' AS [DB Status], 
[1] AS [Test ACC], [2] AS [Test APP], [3] AS [Test DBA], [4] AS [Prod ACC], [5] AS [Prod APP], [6] AS [Prod DBA], [7] AS [Prod], [8] AS [Test], [9] AS [Migrated], [10] AS [Offline], [11] AS [Reserved] 
FROM 
(
    SELECT ID, Name  FROM [DBT].[Status]
) AS Source
PIVOT
(
    COUNT(Name) FOR ID IN ([1], [2], [3], [4], [5], [6], [7], [8], [9], [10], [11])
) AS PivotTable

到目前为止的输出

DB Status       Test ACC    Test APP    Test DBA    Prod ACC    Prod APP    Prod DBA    Prod        Test        Migrated    Offline     Reserved
--------------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- ----------- -----------
Database Status 1           1           1           1           1           1           1           1           1           1           1

db <>小提琴

到目前为止的dbfiddle。

题

我不希望将多个Test... 和Prod....值包含多个行，而是将它们分组，类似于以下内容：

DB Status       | Test | Prod | Migrated | Offline | Reserved   
--------------- | ---- | ---- | -------- | ------- | --------
Database Status |    4 |    4 |        1 |       1 |        1

我不知道如何解决我的问题。（老实说，我只是经过反复试验和错误才昨天才掌握PIVOT）。

这个问题与如何在我已经问过的多个表上创建分组项目的总和/计数松散相关。表[DBT]。[Instance]和[DBT]。[Database]包含具有[StatusID]的列，该列与我们现在正在查看的表相对应。

总和

对于有限数量的名称，您可以通过以下方式使用SUM（CASE解决方案：

SELECT 
    'Database status' as [DB Status],
    SUM(CASE WHEN Name LIKE 'Test%' THEN 1 ELSE 0 END) As Test,
    SUM(CASE WHEN Name LIKE 'Prod%' THEN 1 ELSE 0 END) AS Prod,
    SUM(CASE WHEN Name = 'Migrated' THEN 1 ELSE 0 END) AS Migrated,
    SUM(CASE WHEN Name = 'Offline' THEN 1 ELSE 0 END) AS Offline,
    SUM(CASE WHEN Name = 'Reserved' THEN 1 ELSE 0 END) AS Reserved
FROM 
    [Status];

枢

如果存在大量的名称列表，但仅需重写其中几个名称，则可以维护PIVOT解决方案：

SELECT 'Database Status' AS [DB Status],
[Test], [Prod], [Migrated], [Offline], [Reserved]
FROM
(
    SELECT 
        ID, 
        CASE
            WHEN Name LIKE 'Test%' THEN 'Test'
            WHEN Name LIKE 'Prod%' THEN 'Prod'
            ELSE Name
        END AS Name
    FROM 
        [Status]
) AS Source
PIVOT
(
    COUNT(ID) FOR Name IN ([Test], [Prod], [Migrated], [Offline], [Reserved])
) AS PivotTable;

db <> 在这里拨弄

动态查询

如果您有点懒惰并且不想编写所有列名，则可以使用动态查询：

DECLARE @cols nvarchar(max);

SET @cols = STUFF((SELECT DISTINCT ',' + QUOTENAME(CASE WHEN Name LIKE 'Test%' THEN 'Test'
                                                    WHEN Name LIKE 'Prod%' THEN 'Prod'
                                                    ELSE Name END)
                   FROM [Status]
                   FOR XML PATH(''), TYPE).value('.', 'NVARCHAR(MAX)'), 1, 1, '');

DECLARE @cmd nvarchar(max);

SET @cmd = 
'SELECT ''Database Status'' AS [DB Status],' + @cols + ' FROM
    (SELECT 
        ID, 
        CASE
            WHEN Name LIKE ''Test%'' THEN ''Test''
            WHEN Name LIKE ''Prod%'' THEN ''Prod''
            ELSE Name
        END AS Name
    FROM 
        [Status]
) AS Source
PIVOT
(
    COUNT(ID) FOR Name IN (' + @cols + ')
) PVT'

EXEC(@cmd);

db <> 在这里拨弄

我认为将您要在此处一步一步执行的两个任务严格分开很重要。

1. 分类
2. 转型

为了对数据进行分类，我的直觉是建议使用查找表将记录严格映射到父类。例如

CREATE TABLE StatusType (
  ID     INT         IDENTITY PRIMARY KEY,
  [Name] VARCHAR(10) NOT NULL UNIQUE
);
GO
ALTER TABLE [Status] 
  ADD StatusTypeID INT NOT NULL 
    DEFAULT 1
    FOREIGN KEY REFERENCES StatusType (ID) ;

...其中StatusType（（默认ID为= 1 Status.StatusTypeID）中的种子记录是名为“未知”或类似名称的占位符记录。

当查找数据被播种并使用正确的密钥更新基本记录时，您就可以放心使用。

select 'Database Status' AS [DB Status],
    [Test], [Prod], [Migrated], [Offline], [Reserved]
from (
    select s.ID,
           st.Name as StatusTypeName
    from status s
    join statusType st on st.ID = s.StatusTypeID
) as Source
pivot (
    count(ID) for StatusTypeName in ([Test],[Prod],[Migrated],[Offline],[Reserved],[Unknown])
) as pvt;

完整的dbfiddle