TSQL未能解析XML（命名空间）

Question

Here is a my SQL:

    create table sqm (data xml)    
    insert into sqm
    select '<DataSet xmlns="http://www.bnr.ro/xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.bnr.ro/xsd nbrfxrates.xsd">
            <Cube date="2017-06-30">
                <Rate currency="AED">1.0867</Rate>
                <Rate currency="AUD">3.0665</Rate>
                <Rate currency="BGN">2.3284</Rate>
            </Cube>
            </DataSet>'

    select
    m.c.value('@date', 'date') as valuta
    from sqm as s
    outer apply s.data.nodes('/DataSet/Body/Cube') as m(c)

After spending hours trying to find out why my SQL kept returning NULL in the db, I discovered that my problem was due to Hyperlink references at the very beginning of the XML(after DataSet). I really want to know why is this happening and who can I delete everything between <DataSet end > . Is there any other option?

if you can think of a better title, please edit.

Answer 1

You need to declare the namespace using WITH XMLNAMESPACES

Also your example XML has no Body element so I removed that from the Xpath.

Demo

WITH XMLNAMESPACES (DEFAULT 'http://www.bnr.ro/xsd')  

select
m.c.value('@date', 'date') as valuta
from sqm as s
outer apply s.data.nodes('/DataSet/Cube') as m(c)

Or alternatively you can use

select
m.c.value('@date', 'date') as valuta
from sqm as s
outer apply s.data.nodes('/*:DataSet/*:Cube') as m(c)

Answer 2

Apart of Martin's solutions(+1), there is one more solution that is using inline declaration of XML namespaces thus:

-- Solution #1
select  m.c.value('@date', 'date') as valuta
from    sqm as s
outer apply s.data.nodes('declare default element namespace "http://www.bnr.ro/xsd";DataSet/Cube') as m(c)

-- Solution #2
select  m.c.value('@date', 'date') as valuta
from    sqm as s
outer apply s.data.nodes('
    declare default element namespace "http://www.bnr.ro/xsd";  
    declare namespace xsi="http://www.w3.org/2001/XMLSchema-instance";  
    declare namespace schemaLocation="http://www.bnr.ro/xsd nbrfxrates.xsd";  
    DataSet/Cube') as m(c)