XQuery 过滤器（如Where 子句）

Question

我已根据特定条件从 XML 值中获取数据。 想法是拥有一张包含两列 ID 和 Data（XML 数据类型）的表。我必须获取特定 ID 的数据。

这是示例，我希望仅在西尔斯大厦的第一排获得结果。我得到两行。

IF OBJECT_ID('tempdb..#ExistExample') IS NOT NULL
DROP TABLE #ExistExample
GO

CREATE TABLE #ExistExample
(
  XMLID Int,
  XMLDocument xml
)

INSERT INTO #ExistExample
VALUES (100,'<Buildings>
  <Building>
    <Name>Sears Tower</Name>
    <Floor1>Yes</Floor1>
    <Floor2>Yes</Floor2>
    <Floor3>No</Floor3>
  </Building>
  <Building>
    <Name>IDS Building</Name>
      <Floor1>Yes</Floor1>
      <Floor2>Yes</Floor2>
      <Floor3>Yes</Floor3>
  </Building>
</Buildings>')

DECLARE @data varchar(1000)
DECLARE @ID INT
SET @ID = 101
SET @data = 'Sears Tower'

INSERT INTO #ExistExample
VALUES (101,'<Buildings>
  <Building>
    <Name>Sears Tower</Name>
    <Floor1>Yes</Floor1>
    <Floor2>Yes</Floor2>
    <Floor3>No</Floor3>
  </Building>
  <Building>
    <Name>IDS Building</Name>
      <Floor1>Yes</Floor1>
      <Floor2>Yes</Floor2>
      <Floor3>Yes</Floor3>
  </Building>
</Buildings>')

--SELECT * FROM #ExistExample

SELECT 
c.value('(Name/text())[1]','varchar(25)') AS BuildingName,
c.value('(Floor1/text())[1]','varchar(25)') AS Floor1,
c.value('(Floor2/text())[1]','varchar(25)') AS Floor2,
c.value('(Floor3/text())[1]','varchar(25)') AS Floor3
FROM #ExistExample
CROSS APPLY XMLDocument.nodes('/Buildings/Building') as t(c)
WHERE c.exist('//Building/Name[.=sql:variable("@data")]') = 1
AND XMLID = @ID

Answer 1

使用：

DriverDetails/DriverDetail[ID eq 1]/*[not(self::ID)]

或者，如果您认为这更简单：

DriverDetails/DriverDetail[ID eq 1]/(PRN | Name))

这里假设（对于两个 XPath 表达式）表达式的计算结果是将 DriverDetails 的父节点作为初始上下文节点。

Answer 2

得到答案了。这应该是这样的：

SELECT c.value('(Name/text())[1]','varchar(25)') AS BuildingName, 
c.value('(Floor1/text())[1]','varchar(25)') AS Floor1, 
c.value('(Floor2/text())[1]','varchar(25)') AS Floor2, 
c.value('(Floor3/text())[1]','varchar(25)') AS Floor3
 FROM #ExistExample 
CROSS APPLY XMLDocument.nodes('/Buildings/Building') as t(c) 
WHERE c.value('(Name/text())[1]','varchar(25)') = @data 
AND XMLID = @ID

我不确定这是否是更好的方法，或者还有其他方法可以实现这一目标。