在T-SQL中创建XML：如何生成带多命名空间的Root根节点？

Hey there! Generating that exact Root element with the required namespaces is straightforward using T-SQL's WITH XMLNAMESPACES clause. Here's how you can do it:

First, define all your namespaces upfront with WITH XMLNAMESPACES—this lets you set the default namespace (without a prefix) and the prefixed ones (xs and xsi) that your Root element needs. Then you can construct the Root element, which will inherit these namespaces automatically.

Example Code: #

WITH XMLNAMESPACES (
    DEFAULT 'http://www.bla-bla.org',
    'http://www.w3.org/2001/XMLSchema' AS xs,
    'http://www.w3.org/2001/XMLSchema-instance' AS xsi
)
SELECT '' 
FOR XML PATH('Root'), ELEMENTS;

Breakdown of what this does: #

• DEFAULT 'http://www.bla-bla.org': Sets the default namespace for the Root element, which translates to xmlns="http://www.bla-bla.org" in the output.
• The lines with AS xs and AS xsi: Define the prefixed namespaces for XML Schema and XML Schema Instance, respectively.
• FOR XML PATH('Root'), ELEMENTS: Ensures we generate a well-formed, empty Root element that includes all declared namespaces.

Running this query will output exactly the XML structure you're targeting:

return (<Root xmlns="http://www.bla-bla.org" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"></Root>
)

Bonus: Adding Child Elements Later #

If you need to include child elements inside the Root down the line, you can extend the SELECT statement while keeping the WITH XMLNAMESPACES clause. For example:

WITH XMLNAMESPACES (
    DEFAULT 'http://www.bla-bla.org',
    'http://www.w3.org/2001/XMLSchema' AS xs,
    'http://www.w3.org/2001/XMLSchema-instance' AS xsi
)
SELECT 
    'Sample Data' AS 'Order/ItemID',
    'Blue' AS 'Order/Color'
FOR XML PATH('Root'), ELEMENTS;

This will create a Root element with the same namespaces plus nested child elements under it.

Hope this solves your problem smoothly!

内容的提问来源于stack exchange，提问作者Andrew_Exp