SQL中如何控制XML的输出格式

Question

我正在尝试从 XML 格式的 (SQL Server 2008 R2) 表中检索数据，但似乎无法将其转换为理想的结构。我尝试了各种 FOR XML 模式和连接方法，但我对 XML 的经验很少，并且在此之前没有通过 SQL 处理 XML 输出。

我的数据在名为 XMLResults 的表中，结构如下：

ResultID    Country Product Disposition Results
-----------------------------------------------
1           UK      ABC     Result1     100
2           UK      ABC     Result2     200
3           UK      ABC     Result3     300
4           UK      XYZ     Result1     100
5           UK      XYZ     Result2     200
6           UK      XYZ     Result3     300
7           USA     ABC     Result1     100
8           USA     ABC     Result2     200
9           USA     ABC     Result3     300
10          USA     XYZ     Result1     100
11          USA     XYZ     Result2     200
12          USA     XYZ     Result3     300

目前我有这个查询：

SELECT (SELECT Country,
                (SELECT Product,
                        (SELECT Disposition, Results
                           FROM XMLResults t1
                          WHERE t1.ResultID = t2.ResultID
                            FOR XML PATH ('Dispositions'), TYPE, ELEMENTS
                        )
                   FROM XMLResults t2
                  WHERE t2.ResultID = t3.ResultID
                    FOR XML PATH ('Products'), TYPE, ELEMENTS
                )
          FROM XMLResults t3
         ORDER BY Country, Product
           FOR XML PATH ('Countries'), TYPE, ELEMENTS
        )
   FOR XML PATH('Stats');

这样返回 XML：

<Stats>
  <Countries>
    <Country>UK</Country>
    <Products>
      <Product>ABC</Product>
      <Dispositions>
        <Disposition>Result1</Disposition>
        <Results>100</Results>
      </Dispositions>
    </Products>
  </Countries>
  <Countries>
    <Country>UK</Country>
    <Products>
      <Product>ABC</Product>
      <Dispositions>
        <Disposition>Result2</Disposition>
        <Results>200</Results>
      </Dispositions>
    </Products>
  </Countries>
  <Countries>
    <Country>UK</Country>
    <Products>
      <Product>ABC</Product>
      <Dispositions>
        <Disposition>Result3</Disposition>
        <Results>300</Results>
      </Dispositions>
    </Products>
  </Countries>
  ...
</Stats>

不是很糟糕，但我希望它不要在每个结果之后一直回到“国家”级别，并且可能也不需要额外的通用标签。

这样的东西会更好：

<Stats>
  <Countries>
    <Country = "UK">
      <Products>
        <Product = "ABC">
          <Dispositions>
            <Disposition>
              <ReasonCode>Result1</ReasonCode>
              <Count>100</Count>
            </Disposition>
            <Disposition>
              <ReasonCode>Result2</ReasonCode>
              <Count>200</Count>
            </Disposition>
            <Disposition>
              <ReasonCode>Result3</ReasonCode>
              <Count>300</Count>
            </Disposition>
          </Dispositions>
        </Product>
        ...
      </Products>
    </Country>
    ...
  </Countries>
</Stats>

甚至可能是这样的（看起来更干净一些）：

<Stats>
  <Country = "UK">
    <Product = "ABC">
      <Disposition ReasonCode = "Result1" Count = "100" />
      <Disposition ReasonCode = "Result2" Count = "200" />
      <Disposition ReasonCode = "Result3" Count = "300" />
    </Product>
    <Product = "XYZ">
      <Disposition ReasonCode = "Result1" Count = "100" />
      <Disposition ReasonCode = "Result2" Count = "200" />
      <Disposition ReasonCode = "Result3" Count = "300" />
    </Product>
  </Country>
  <Country = "USA">
    <Product = "ABC">
      <Disposition ReasonCode = "Result1" Count = "100" />
      <Disposition ReasonCode = "Result2" Count = "200" />
      <Disposition ReasonCode = "Result3" Count = "300" />
    </Product>
    <Product = "XYZ">
      <Disposition ReasonCode = "Result1" Count = "100" />
      <Disposition ReasonCode = "Result2" Count = "200" />
      <Disposition ReasonCode = "Result3" Count = "300" />
    </Product>
  </Country>
</Stats>

输出格式不是一成不变的，所以如果有建议，我也愿意接受建议。

谢谢， 肖恩

---

编辑样本数据：

CREATE TABLE XMLResults (
      ResultID BIGINT IDENTITY(1,1) NOT NULL
    , Country VARCHAR(50) NOT NULL
    , Product VARCHAR(50) NOT NULL
    , Disposition VARCHAR(50) NOT NULL
    , Results INT NOT NULL);

INSERT INTO XMLResults (Country, Product, Disposition, Results)
VALUES ('UK',  'ABC', 'Result1', 100)
     , ('UK',  'ABC', 'Result2', 200)
     , ('UK',  'ABC', 'Result3', 300)
     , ('UK',  'XYZ', 'Result1', 100)
     , ('UK',  'XYZ', 'Result2', 200)
     , ('UK',  'XYZ', 'Result3', 300)
     , ('USA', 'ABC', 'Result1', 100)
     , ('USA', 'ABC', 'Result2', 200)
     , ('USA', 'ABC', 'Result3', 300)
     , ('USA', 'XYZ', 'Result1', 100)
     , ('USA', 'XYZ', 'Result2', 200)
     , ('USA', 'XYZ', 'Result3', 300);

Answer 1

如果您想要以属性为中心的 xml，请在列别名前添加“@”。您可以完全自定义输出，例如：

SELECT
  Country [@Country],
  (SELECT
    Product [@Product],
    (SELECT
      Disposition [@ReasonCode],
      Results [@Count]
    FROM #XMLResults t3
    WHERE t3.Country = t1.Country AND t3.Product = t2.Product
    FOR XML PATH('Disposition'),TYPE)
  FROM #XMLResults  t2
  WHERE t2.Country = t1.Country
  GROUP BY Product
  FOR XML PATH('Product'),TYPE)
FROM #XMLResults  t1
GROUP BY Country
FOR XML PATH('Country'), ROOT ('Stats')

随便玩玩吧。