枢而变化的数据类型(动态)

让我们说有3个表：用户，customattributes，并customattributevalues. 终端用户可以增加定义的特性通过选择一个姓名和类型的属性，和编辑值为任何用户。

这里是我的用户：

customattributes(可以被添加到随时)

类型I目前有作为sysname数据类型。

customattributevalues(可以随时随地进行编辑)

值，我目前有作为 sql_variant 数据类型

因此，这里是我的问题：如何创建一份报告，显示了所有的雇员和他们的属性，1条，每个雇员，不知道有多少自定属性存在--和-- 最重要的是，我要明确转换的每个列为正确的数据类型

期望输出：

我已经学到了要做的动态列标题使用 的动态查询，但它是类型的转换，这是逃避我.

我在适应 这一解决方案定义的领域，但该限于这个方案是，你必须知道每个定义的领域做出的类型转换。

这里是我已经试过了。 我得到了正确的输出，除了为的类型转换。

查询:

DECLARE @columns NVARCHAR(MAX) = '';
DECLARE @sqlcmd NVARCHAR(MAX) = '';

SELECT @columns += QUOTENAME(fullname) + ','
FROM customattributesx ca

ORDER BY ca.id;

SET @columns = LEFT(@columns, LEN(@columns) - 1);

--PRINT @columns;

SET @sqlcmd = '
SELECT * FROM (
    SELECT userid
        ,firstname
        ,lastname
        ,datecreated
        ,username
        ,email
        ,fullname
        ,value
    FROM (
        SELECT u.id as userid
              ,u.firstname
              ,u.lastname
              ,u.datecreated
              ,u.username
              ,u.email
              ,ca.id
              ,ca.fullname as fullname
              ,ca.uniquename
              ,ca.type
              ,cav.value as value
        FROM dbo.users u
        CROSS JOIN customattributesx ca
        INNER JOIN customattributevaluesx cav
            ON cav.attributeid = ca.id AND cav.userid = u.id

        --ORDER BY u.id asc, ca.id asc
    ) t1
) t2
PIVOT (
    MIN(value)
    FOR fullname IN ('+@columns+')
) as pivottable
';
--print @sqlcmd
EXECUTE (@sqlcmd)

创建表：

USE [CTMS]
GO

/****** Object:  Table [dbo].[users]    Script Date: 11/24/2021 9:29:16 AM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE IF NOT EXISTS [dbo].[users](
    [id] [int] IDENTITY(1,1) NOT NULL,
    [firstname] [nvarchar](max) NULL,
    [lastname] [nvarchar](max) NULL,
    [active] [bit] NOT NULL,
    [datecreated] [datetime2](7) NOT NULL,
    [username] [nvarchar](256) NULL,
    [email] [nvarchar](256) NULL,
    [emailconfirmed] [bit] NOT NULL,
    [passwordhash] [nvarchar](max) NULL,
    [twofactorenabled] [bit] NOT NULL,
    [lockoutend] [datetimeoffset](7) NULL,
    [eockoutenabled] [bit] NOT NULL,
    [accessfailedcount] [int] NOT NULL,
    [qrcode] [nvarchar](50) NULL,
 CONSTRAINT [PK_id] PRIMARY KEY CLUSTERED 
(
    [id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY],
 CONSTRAINT [uk_email] UNIQUE NONCLUSTERED 
(
    [email] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY],
 CONSTRAINT [uk_qrcode] UNIQUE NONCLUSTERED 
(
    [qrcode] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY],
 CONSTRAINT [uk_username] UNIQUE NONCLUSTERED 
(
    [username] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO

ALTER TABLE [dbo].[users] ADD  DEFAULT (getutcdate()) FOR [datecreated]
GO


USE [CTMS]
GO

/****** Object:  Table [dbo].[customattributesx]    Script Date: 11/24/2021 9:31:09 AM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE IF NOT EXISTS [dbo].[customattributesx](
    [id] [smallint] IDENTITY(1,1) NOT NULL,
    [fullname] [nvarchar](50) NOT NULL,
    [uniquename] [nvarchar](50) NOT NULL,
    [type] [sysname] NOT NULL,
 CONSTRAINT [PK_customattributesx] PRIMARY KEY CLUSTERED 
(
    [id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY],
 CONSTRAINT [uk1_customattributesx] UNIQUE NONCLUSTERED 
(
    [uniquename] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
GO

USE [CTMS]
GO

/****** Object:  Table [dbo].[customattributevaluesx]    Script Date: 11/24/2021 9:31:27 AM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

CREATE TABLE IF NOT EXISTS [dbo].[customattributevaluesx](
    [id] [int] IDENTITY(1,1) NOT NULL,
    [attributeid] [smallint] NOT NULL,
    [userid] [int] NOT NULL,
    [value] [sql_variant] NOT NULL,
 CONSTRAINT [PK_customattributevaluesx] PRIMARY KEY CLUSTERED 
(
    [id] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY],
 CONSTRAINT [uk1_customattributevaluesx] UNIQUE NONCLUSTERED 
(
    [attributeid] ASC,
    [userid] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON, OPTIMIZE_FOR_SEQUENTIAL_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]
GO

ALTER TABLE [dbo].[customattributevaluesx]  WITH CHECK ADD  CONSTRAINT [fk1_customattributesvaluesx] FOREIGN KEY([attributeid])
REFERENCES [dbo].[customattributesx] ([id])
GO

ALTER TABLE [dbo].[customattributevaluesx] CHECK CONSTRAINT [fk1_customattributesvaluesx]
GO

ALTER TABLE [dbo].[customattributevaluesx]  WITH CHECK ADD  CONSTRAINT [fk2_customattributesvaluesx] FOREIGN KEY([userid])
REFERENCES [dbo].[users] ([id])
GO

ALTER TABLE [dbo].[customattributevaluesx] CHECK CONSTRAINT [fk2_customattributesvaluesx]
GO