Query XML field with T-SQL - sql-server

Question

How can I query multiple nodes in XML data with T-SQL and have the result output to a single comma separated string?
For example, I'd like to get a list of all the destination names in the following XML to look like "Germany, France, UK, Italy, Spain, Portugal"
<Holidays>
<Summer>
<Regions>
<Destinations>
<Destination Name="Germany" />
<Destination Name="France" />
<Destination Name="UK" />
<Destination Name="Italy" />
<Destination Name="Spain" />
<Destination Name="Portugal" />
</Destinations>
<Regions>
</Summer>
</Holidays>
I was trying something like:
Countries = [xmlstring].value('/Holidays/Summer/Regions/Destinations/#Name', 'varchar')

Answer 1

First, to get a list of records from a source XML table, you need to use the .nodes function (DEMO):
select Destination.value('data(#Name)', 'varchar(50)') as name
from [xmlstring].nodes('/Holidays/Summer/Regions/Destinations/Destination')
D(Destination)
Sample output:
| NAME |
-------------
| Germany |
| France |
| UK |
| Italy |
| Spain |
| Portugal |
From here, you want to concatenate the destination values into a comma-separated list. Unfortunately, this is not directly supported by T-SQL, so you'll have to use some sort of workaround. If you're working with a source table using multiple rows, the simplest method is the FOR XML PATH('') trick. In this query I use a source table called Data, and split out the XML into separate records, which I then CROSS APPLY with FOR XML PATH('') to generate comma-separated rows. Finally, the final , is stripped from the result to create the list (DEMO):
;with Destinations as (
select id, name
from Data
cross apply (
select Destination.value('data(#Name)', 'varchar(50)') as name
from [xmlstring].nodes('/Holidays/Summer/Regions/Destinations/Destination') D(Destination)
) Destinations(Name)
)
select id, substring(NameList, 1, len(namelist) - 1)
from Destinations as parent
cross apply (
select name + ','
from Destinations as child
where parent.id = child.id
for xml path ('')
) DestList(NameList)
group by id, NameList
Sample Output (Note that I've added another XML fragment to the test data to make a more complex example):
| ID | COLUMN_1 |
-----------------------------------------------
| 1 | Germany,France,UK,Italy,Spain,Portugal |
| 2 | USA,Australia,Brazil |