如何从 T-SQL 中的 XML 列中获取以逗号分隔的字符串列表？

Question

Suppose there is a table (SQL Server 2019) with two columns. Both are nvarchar but the ResultDoc column happens to store xml. Example data:

Name	ResultDoc
Sam	<doc><results><result>a</result><result>b</result><result>x</result></results></doc>
Jan	<doc><results><result>c</result><result type="pending">z</result><result>m</result><result>k</result></results></doc>

I want to be able to query this table, filtering on the xml, and get a result like this:

Name	Results
Sam	a, b, x
Jan	c, m, k

I've seen examples that do this for a single document, but I haven't been able to work a solution like that into a query that does this for several rows.

Answer 1

Updated ... moved the aggregate into the OUTER APPLY

Since you are on 2019, you can use string_agg()

Example or dbFiddle

Select A.Name
      ,C.Results
 From  YourTable A
 Outer Apply ( values (try_convert(xml,[ResultDoc]) ) )B(xmlData)
 Outer Apply (
                Select Results = string_Agg(xn.value('./text()[1]', 'nvarchar(150)'),',')
                 From xmlData.nodes('doc/results/result') C(xn)
                 Where coalesce(xn.value('@type[1]', 'nvarchar(150)'),'') not in ('pending')
              ) C

Results

Name    Results
Jan     c,m,k
Sam     a,b,x