sql - 将 XML 数据分解为 SQL 行时保留元素顺序

Question

在 SQL Server View 中将 XML 分解为行时如何返回元素序列？

示例输入:

<ol>
  <li>Smith</li>
  <li>Jones</li>
  <li>Brown</li>
</ol>

期望的输出:

Sequence  Name
--------  -----------
    1     Smith
    2     Jones
    3     Brown

现有 View :

CREATE VIEW OrderedList
AS
SELECT [Sequence] = CAST(NULL AS int)   -- TODO: Get ordinal position
       [Name] = b.b.value('.', 'nvarchar(max)')
FROM
(
    SELECT a = CAST('<ol><li>Smith</li><li>Jones</li><li>Brown</li></ol>' AS xml)
) a
CROSS APPLY a.a.nodes('/ol/li') b (b)

Answer 1

您可以在 xml 节点上使用 row_number()。

CREATE VIEW OrderedList
AS
SELECT [Sequence] = ROW_NUMBER() OVER(ORDER BY b.b),
       [Name] = b.b.value('.', 'nvarchar(max)')
FROM
(
    SELECT a = CAST('<ol><li>Smith</li><li>Jones</li><li>Brown</li></ol>' AS xml)
) a
CROSS APPLY a.a.nodes('/ol/li') b (b)

引用号:Uniquely Identifying XML Nodes with DENSE_RANK 作者:亚当·马卡尼克。