T-Sql xml query with namespace

问题:

This is a follow up question to

T-Sql xml query

If I add a namespace to xml data, nothing is returned again.

DECLARE @xVar XML
SET @xVar = 
  '<ReportData ObjectId="123" xmlns="http://ait.com/reportdata">
  <ReportId>AAAA-BBBB-CCCCC-DDDDD</ReportId>
  <DocId>100</DocId>
  <ReportName>Drag Scraper Troubleshooting</ReportName>
  <DocType>Name</DocType>
  <StatusId>1</StatusId>
  <AuthorId>1</AuthorId>
   </ReportData>'

SELECT [ReportId]= reportdata.item.value('.', 'varchar(40)') 
FROM   @xVar.nodes('/ReportData/ReportId[1]') AS reportdata(item) 

The above query returns nothing. Secondly, how would I select all elements in a single select and return a row with all elements as fields?

I want to return a record constructed as the following:

ReportId              | DocId | ReportName | 
AAAA-BBBB-CCCCC-DDDDD | 100   | AAAA-BBBB-CCCCC-DDDDD |

回答1:

Look at WITH XMLNAMESPACES

;WITH XMLNAMESPACES(DEFAULT 'http://ait.com/reportdata')
SELECT [ReportId]= reportdata.item.value('.', 'varchar(40)') 
FROM   @xVar.nodes('/ReportData/ReportId[1]') AS reportdata(item) 

回答2:

If my assumptions are correct and you want to list ALL ReportData elements in your XML document and want their child elements as different columns, you could look at something like this:

;WITH XMLNAMESPACES(DEFAULT 'http://ait.com/reportdata')
SELECT 
    [ReportId] = reportdata.item.value('(./ReportId)[1]', 'varchar(40)') 
  , [DocId] = reportdata.item.value('(./DocId)[1]', 'varchar(40)') 
  , [ReportName] = reportdata.item.value('(./ReportName)[1]', 'varchar(40)') 
  , [DocType] = reportdata.item.value('(./DocType)[1]', 'varchar(40)') 
  , [StatusId] = reportdata.item.value('(./StatusId)[1]', 'varchar(40)') 
  , [AuthorId] = reportdata.item.value('(./AuthorId)[1]', 'varchar(40)') 
FROM @xVar.nodes('//ReportData') AS reportdata(item)

I'll need to look at cleaning up the namespace declarations a bit, but it seems to work for me...

EDIT: Amended my answer with the WITH XMLNAMESPACES clause as recommended by Martin. :)