SQL Server : Count of XML Elements By Element Name - sql

Question

I have successfully obtained a count of sub elements using this query.
SELECT
raa.ApplicationXML.value('count(Root/ThirdParty/*)', 'Int') as [Bureau Count]
FROM
Table1 raa
However, I want to group this count by the actual name of the sub element.
My XML looks something like this:
Record 1:
<Root>
<ThirdParty>
<BureauRed />
<BureauGreen />
<BureauBlue />
</ThirdParty>
</Root>
Record 2:
<Root>
<ThirdParty>
<BureauRed />
<BureauPurple />
<BureauBlue />
</ThirdParty>
</Root>
Record 3:
<Root>
<ThirdParty>
<BureauGreen />
<BureauRed />
<BureauPurple />
<BureauOrange />
<BureauBlue />
</ThirdParty>
</Root>
Not only do I need to pull the count of each bureau, but I need to get the name of the bureau (BureauRed, BureauGreen, BureauBlue, etc.) When I try to group by count I get the error:
XML methods are not allowed in a GROUP BY clause.
Using this query:
SELECT
raa.ApplicationXML.value('count(Root/ThirdParty/*)', 'Int') as [Bureau Count]
FROM
Table1 raa
GROUP BY
raa.ApplicationXML.value('count(Root/ThirdParty/*)', 'Int')
How do I get the count and the name of the bureau?
I'm looking for this result:
Bureau Count
============ =====
BureauRed 3
BureauGreen 2
BureauBlue 3
BureauPurple 2
BureauOrange 1

Answer 1

You can group after recieving data via XQuery:
DECLARE #xml1 xml =
'<Root>
<ThirdParty>
<BureauRed />
<BureauGreen />
<BureauBlue />
</ThirdParty>
</Root>';
DECLARE #xml2 xml =
'<Root>
<ThirdParty>
<BureauRed />
<BureauPurple />
<BureauBlue />
</ThirdParty>
</Root>';
DECLARE #xml3 xml =
'<Root>
<ThirdParty>
<BureauGreen />
<BureauRed />
<BureauPurple />
<BureauOrange />
<BureauBlue />
</ThirdParty>
</Root>';
DECLARE #temp TABLE (XmlData xml);
INSERT #temp VALUES (#xml1), (#xml2), (#xml3);
WITH cte AS
(
SELECT n.value('local-name(.)', 'varchar(50)') nodeName
FROM #temp t
CROSS APPLY t.XmlData.nodes('/Root/ThirdParty/*') x(n)
)
SELECT nodeName, count(*) cnt
FROM cte
GROUP BY nodeName;
Output:
nodeName cnt
-------------------------------------------------- -----------
BureauBlue 3
BureauGreen 2
BureauOrange 1
BureauPurple 2
BureauRed 3

Answer 2

You need to extract the elements that are children of Root/ThirdParty first and use that derived table to do the counting.
DECLARE #tv TABLE(x XML);
INSERT INTO #tv(x)VALUES(
N'<Root>
<ThirdParty>
<BureauRed />
<BureauGreen />
<BureauBlue />
</ThirdParty>
</Root>'),(
N'<Root>
<ThirdParty>
<BureauRed />
<BureauPurple />
<BureauBlue />
</ThirdParty>
</Root>'),(
N'<Root>
<ThirdParty>
<BureauGreen />
<BureauRed />
<BureauPurple />
<BureauOrange />
<BureauBlue />
</ThirdParty>
</Root>');
WITH bureaus AS (
SELECT
bureau=n.v.value('local-name(.)','NVARCHAR(256)')
FROM
#tv
CROSS APPLY x.nodes('/Root/ThirdParty/*') AS n(v)
)
SELECT
bureau,
[count]=COUNT(*)
FROM
bureaus
GROUP BY
bureau
ORDER BY
bureau;