generate structured (xml) document from hierarchical table data (T-SQL)

Question

I have a table like this (simplified):

ID   |   Name  |   Parent
---------------------------------
1    |  IND    |   NULL
2    |  INS    |   5
3    |  CON           


        

Answer 1

Based on Recep's answer (see comments) I created the following solution for this problem:

1. Create a recursive function

CREATE function SelectChild(@key as int)
returns xml
begin
    return (
        select 
            IdIndustry as "@key", 
            ParentId as "@parentkey",
            IndustryCode as "@Code",
            IndustryName as "@Name",
            dbo.SelectChild(IdIndustry)
        from tblIndustryCodes
        where ParentId = @key
        for xml path('record'), type
    )
end

2. Build a SELECT statement, that calls the function

SELECT 
    IdIndustry AS "@key", 
    '' AS "@parentkey",
    IndustryCode as "@Code",
    IndustryName as "@Name",
    dbo.SelectChild(IdIndustry)     
FROM dbo.tblIndustryCodes
WHERE ParentId is null
FOR XML PATH ('record')

This creates a hierarchical XML, no matter how deep the tree actually is: