SQL Query to Pars Out a Value from NTEXT (XML format) field - sql

Question

I have XML data in an NTEXT field (ou.ORDMODE), that I need to parse out a value (description) from. Column may contain null values. The data looks like this:
<?xml version="1.0" encoding="utf-16"?>
<UDFValidatedValue xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/Accellos.Platform.UDF">
<Description>Export</Description>
<Value>EXP</Value>
<ValueType>String</ValueType>
</UDFValidatedValue>
The line I have in my query is this:
CAST(REPLACE(CAST(ou.ORDMODE as NVARCHAR(MAX)),' xmlns="http://schemas.datacontract.org/2004/07/Accellos.Platform.UDF"','') as XML).value ('(/UDFValidatedValue/Description/text())[0]', 'nvarchar(100)') as Mode3,
but Mode3 column is returned as blank.
What am I doing wrong?

Answer 1

You could use this:
DEclare #xml xml = N'<?xml version="1.0" encoding="utf-16"?>
<UDFValidatedValue xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/Accellos.Platform.UDF">
<Description>Export</Description>
<Value>EXP</Value>
<ValueType>String</ValueType>
</UDFValidatedValue>';
;WITH XMLNAMESPACES(DEFAULT 'http://schemas.datacontract.org/2004/07/Accellos.Platform.UDF')
select #xml.value ('(/UDFValidatedValue/Description)[1]', 'nvarchar(100)') as Mode3
or
select #xml.value ('declare namespace
udf="http://schemas.datacontract.org/2004/07/Accellos.Platform.UDF";
(/udf:UDFValidatedValue/udf:Description)[1]', 'nvarchar(100)') as Mode3
Demo link: Rextester

Answer 2

As ZLK pointed out in his comment, your own approach seems to be quite okay, just the index must be 1 instead of 0. Try it here:
ad "quite okay": Actually this is absolutely far away from "quite okay", read my hint below...
DECLARE #tbl TABLE(SomeXmlInText TEXT);
INSERT INTO #tbl VALUES
('<?xml version="1.0" encoding="utf-16"?>
<UDFValidatedValue xmlns:i="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://schemas.datacontract.org/2004/07/Accellos.Platform.UDF">
<Description>Export</Description>
<Value>EXP</Value>
<ValueType>String</ValueType>
</UDFValidatedValue>');
SELECT SomeXmlInText
,CAST(REPLACE(CAST(SomeXmlInText as NVARCHAR(MAX)),' xmlns="http://schemas.datacontract.org/2004/07/Accellos.Platform.UDF"','') as XML).value ('(/UDFValidatedValue/Description/text())[1]', 'nvarchar(100)') as Mode3
FROM #tbl
From your answer I take, that there is still no result...
Some possible issues:
XML is not really as you expect it
more / other namespaces
some weird no, not for you issue :-D
Hint
As you probably know TEXT, NTEXT and IMAGE are deprecated for centuries and should really not be used any more... If you have the slightest chance to change this, then you should store your XML in the appropritate XML-type...
You should not need any casts or manipulations on string level. This can be working, but is really out-dated...