如何使用 FOR XML AUTO 子句将特定列 return 作为元素

Question

我需要 return 一个特定的列作为 xml 中的一个元素 return 使用 sql 服务器中的 FOR XML AUTO 子句编辑. Automatic return 把所有字段都变成相应元素的属性。好的，但是我需要一个字段或另一个字段作为一个元素。

我有两个表：

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Table1](
    [Id] [int] NULL,
    [Nome] [varchar](50) NULL
) ON [PRIMARY]
GO
/****** Object:  Table [dbo].[Table2]    Script Date: 02/03/2018 16:24:11 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Table2](
    [Id] [int] NULL,
    [DataVencimento] [date] NULL,
    [Table1_Id] [int] NULL
) ON [PRIMARY]
GO
INSERT [dbo].[Table1] ([Id], [Nome]) VALUES (1, N'AAA')
GO
INSERT [dbo].[Table1] ([Id], [Nome]) VALUES (2, N'BBB')
GO
INSERT [dbo].[Table1] ([Id], [Nome]) VALUES (3, N'CCC')
GO
INSERT [dbo].[Table2] ([Id], [DataVencimento], [Table1_Id]) VALUES (1, CAST(N'2018-01-01' AS Date), 1)
GO
INSERT [dbo].[Table2] ([Id], [DataVencimento], [Table1_Id]) VALUES (2, CAST(N'2018-01-02' AS Date), 2)
GO
INSERT [dbo].[Table2] ([Id], [DataVencimento], [Table1_Id]) VALUES (3, CAST(N'2018-01-03' AS Date), 2)
GO

我认为他们之间有如下关系：

select 
    Table1.Id,
    Table1.Nome,
    Table2.Id,
    Table2.DataVencimento
from Table1 
    inner join Table2 on Table2.Table1_Id = Table1.Id
    order by Table1.Id, Table2.Id
for xml auto, root('ArrayOfTable1')

其中 return 个：

<ArrayOfTable1>
  <Table1 Id="1" Nome="AAA">
    <Table2 Id="1" DataVencimento="2018-01-01" />
  </Table1>
  <Table1 Id="2" Nome="BBB">
    <Table2 Id="2" DataVencimento="2018-01-02" />
    <Table2 Id="3" DataVencimento="2018-01-03" />
  </Table1>
</ArrayOfTable1>

但是我需要 DataVencimento 作为一个元素，像这样：

<ArrayOfTable1>
    <Table1 Id="1" Nome="AAA">
        <Table2 Id="1">
            <DataVencimento>2018-01-01</DataVencimento>
        </Table2>
    </Table1>
    <Table1 Id="2" Nome="BBB">
        <Table2 Id="2">
            <DataVencimento>2018-01-02</DataVencimento>
        </Table2>
        <Table2 Id="3">
            <DataVencimento>2018-01-03</DataVencimento>
        </Table2>
    </Table1>
</ArrayOfTable1>

如何操作？

Answer 1

我现在不知道是否有更清洁的解决方案，但像这样的方法应该可行：

select 
    Table1.Id as [@Id],
    Table1.Nome as [@Nome],
    [inner].[xml] as [*]
from Table1 
outer apply 
( select (select
     Table2.Id as [@Id],
    Table2.DataVencimento
  from Table2 
  where Table2.Table1_Id = Table1.Id
  for xml path('Table2'), type) as [xml]

) as [inner]
    inner join Table2 on Table2.Table1_Id = Table1.Id
    order by Table1.Id, Table2.Id
for xml path('Table1'), root('ArrayOfTable1')

Answer 2

select 
    Table1.ID,
    Table1.Nome,
    Table2.Id,
    (select table2.DataVencimento for xml path(''), elements, type)
from Table1 
    inner join Table2 on Table2.Table1_Id = Table1.Id
order by Table1.Id, Table2.Id
for xml auto, root('ArrayOfTable1')

输出：

<ArrayOfTable1>
  <Table1 ID="1" Nome="AAA">
    <Table2 Id="1">
      <DataVencimento>2018-01-01</DataVencimento>
    </Table2>
  </Table1>
<Table1 ID="2" Nome="BBB">
  <Table2 Id="2">
    <DataVencimento>2018-01-02</DataVencimento>
  </Table2>
  <Table2 Id="3">
    <DataVencimento>2018-01-03</DataVencimento>
  </Table2>
</Table1>
</ArrayOfTable1>

http://sqlfiddle.com/#!18/71fe9/29

Answer 3

在大多数情况下，FOR XML PATH() 是首选方法。使用 PATH 您可以完全控制输出。没有什么是自动...

试试看：

SELECT t1.Id AS [@id]
      ,t1.Nome AS [@Nome]
      ,(
        SELECT t2.Id AS [@Id]
              ,t2.DataVencimento
        FROM dbo.Table2 AS t2
        WHERE t1.Id=t2.Table1_Id
        ORDER BY t2.Id
        FOR XML PATH('Table2'),TYPE
       )
FROM dbo.Table1 AS t1
WHERE EXISTS(SELECT 1 FROM dbo.Table2 WHERE Table2.Table1_Id=t1.Id)
ORDER BY t1.Id
FOR XML PATH('Table1'), ROOT('ArrayOfTable1');

如何使用 FOR XML AUTO 子句将特定列 return 作为元素

How to return a specific column as an element with FOR XML AUTO clause

sql-server

xml

for-xml