SQL Server column containing XML needs to be concatentated - sql

Question

I have a sql server 2008 r2 database that contains a table with raw XML in one of the columns. I have written a query to extract data from this table using group by and stuff to concatenate all of the columns that meet a 2 column group by clause. The issue is that when I stuff the columns I get duplicate XML declarations and the XML is not valid.
<?xml version="1.0" encoding="UTF-8"?>
<Fruits>
<Fruit Type="Lemons" Price="0.50" />
<Fruit Type="Apples" Price="0.75" />
</Fruits>
<?xml version="1.0" encoding="UTF-8"?>
<Fruits>
<Fruit Type="Cherries" Price="0.10" />
<Fruit Type="Dates" Price="0.25" />
</Fruits>
I looked at adding a substring call to remove this declaration but the query is getting quite complex and slow. I am working with an XSLT transformer that creates XML output. In the end I have many rows that can be delivered to a common destination. I basically need a way to concatenate the XML while removing the duplicate XML declarations and handling the XML hierarchy
This would be converted to
<?xml version="1.0" encoding="UTF-8"?>
<Fruits>
<Fruit Type="Lemons" Price="0.50" />
<Fruit Type="Apples" Price="0.75" />
<Fruit Type="Cherries" Price="0.10" />
<Fruit Type="Dates" Price="0.25" />
</Fruits>
Does anyone know how to do this in a systematic way? I am not actually working with fruit but used it as a simplified example.
Here is the actual query
SELECT tt.ProductCodeID, tt.ProviderID, tt.ContentXML, LEN(tt.ContentXML) AS xmllength from
(SELECT p.ProductCodeID, l.ProviderID,
STUFF((
SELECT pl1.Content FROM dbo.Payload pl1
INNER JOIN Log l1 ON pl1.LogID=l1.LogID
INNER JOIN Provider p1 ON l1.ProviderID=p1.ProviderID
WHERE pl1.ProductCodeID=p.ProductCodeID AND
pl1.PayloadTypeID=pt.PayloadTypeID
AND p1.ProviderID=l.ProviderID
FOR XML PATH(''), TYPE).value('.','varchar(max)'),1,1,'') AS ContentXML
FROM dbo.Queue q
INNER JOIN log l ON q.LogID=l.LogID
INNER JOIN payload pl ON l.LogID=pl.LogID
INNER JOIN dbo.PayloadType pt ON pl.PayloadTypeID = pt.PayloadTypeID
INNER JOIN dbo.ProductCode p ON pl.ProductCodeID= p.ProductCodeID
INNER JOIN dbo.Status s ON q.StatusID=s.StatusID
WHERE s.Name = 'processed' AND pt.Name='MIF'
GROUP BY p.ProductCodeID, l.ProviderID, pt.PayloadTypeID) AS tt
Thank you

Answer 1

It's ugly, but if you always know what the objects are going to be you could strip out the xml you don't want.
SELECT ..., '<?xml version="1.0" encoding="UTF-8"?><Fruits>' +
REPLACE( REPLACE(xml_column,
'<?xml version="1.0" encoding="UTF-8"?><Fruits>',
''),
'</Fruits',
'') +
'</Fruits>
Or, use a similar step to preprocess the data, and use the replace function to add a column missing the xml headers.

Answer 2

This one is the quick solution that I can think of right now.
CREATE TABLE Test2(ID INT,Col1 XML, Col2 XML)
INSERT INTO Test2 VALUES(1,'<?xml version="1.0" encoding="UTF-8"?><Fruits><Fruit Type="Lemons" Price="0.10" /><Fruit Type="Apples" Price="0.25" /></Fruits>','<?xml version="1.0" encoding="UTF-8"?><Fruits><Fruit Type="Cherries" Price="0.10" /><Fruit Type="Dates" Price="0.25" /></Fruits>')
INSERT INTO Test2 VALUES(2,'<?xml version="1.0" encoding="UTF-8"?><Fruits><Fruit Type="Lemons2" Price="0.10" /><Fruit Type="Apples2" Price="0.25" /></Fruits>','<?xml version="1.0" encoding="UTF-8"?><Fruits><Fruit Type="Cherries2" Price="0.10" /><Fruit Type="Dates3" Price="0.25" /></Fruits>')
SELECT ID, (
SELECT Fruit,Price FROM(
SELECT
Tbl.Col.value('#Type', 'varchar(100)') AS Fruit,
Tbl.Col.value('#Price', 'varchar(10)') AS Price
FROM Col1.nodes('//Fruit') Tbl(Col)
UNION
SELECT
Tbl.Col.value('#Type', 'varchar(100)'),
Tbl.Col.value('#Price', 'varchar(10)')
FROM Col2.nodes('//Fruit') Tbl(Col)) Fruits FOR XML AUTO
) FROM Test2