SQL xml multilevel structure from one table

Question

I have a table in MS SQL Server database which has a structure like this:

 | goodId | pos     | description | docType        | isKey |
 +--------+---------+-------------+----------------+-------+
 | 1417   | NULL    | List 1050   | 1050.0000.0000 | 0     |
 | 1417   | 2.1.1.1 | hgfhgf9     | 1050.0002.0000 | 1     |
 | 1417   | 2.1.1.2 | hghgfh0     | 1050.0002.0000 | 1     |
 | 1417   | 2.1.1.3 | wwwwww      | 1050.0002.0000 | 1     |
 | 1417   | NULL    | List 1030   | 1030.0000.0000 | 0     |
 | 1417   | 1.3.7.6 | tdgfdgfd    | 1030.0001.0001 | 1     |
 | 1417   | 9.2.1.2 | gdfgfdfd    | 1030.0001.0009 | 1     |
 | 1417   | 9.2.1   | dddddddd    | 1030.0002.0009 | 1     |

In the last column [docType] first 4 characters mean the number of the list, next 4 characters mean the number of the part. I need to take positions where isKey = 1, but description for the list should be taken from the row where only 4 first charcters are filled(it will be description for that list)

I want to get an XML structure from this table using SQL XML like that:

 <good Id="1417">
  <list num="1050" description="List 1050"> 
    <part num="2">
      <pos num = "2.1.1.1"/>
      <pos num= "2.1.1.2"/>
      <pos num= "2.1.1.3"/>
    </part>
  </list>
  <list num="1030" description="List 1030">
    <part num="1">
      <pos num = "1.3.7.6"/>
      <pos num = "9.2.1.2"/>
    </part>
    <part num="2">
      <pos num = "9.2.1"/>
    </part>
  </list>
</good>

What query should I write to get this XML structure?

Answer 1

Monstrous query.

declare @MyTable table (goodId int, pos varchar(100), description varchar(100), docType varchar(100), isKey bit)

insert into @MyTable (goodId, pos, description, docType, isKey) values
(1417,  NULL,     'List 1050', '1050.0000.0000', 0),
(1417, '2.1.1.1', 'hgfhgf9',   '1050.0002.0000', 1),
(1417, '2.1.1.2', 'hghgfh0',   '1050.0002.0000', 1),
(1417, '2.1.1.3', 'wwwwww',    '1050.0002.0000', 1),
(1417,  NULL,     'List 1030', '1030.0000.0000', 0),
(1417, '1.3.7.6', 'tdgfdgfd',  '1030.0001.0001', 1),
(1417, '9.2.1.2', 'gdfgfdfd',  '1030.0001.0009', 1),
(1417, '9.2.1',   'dddddddd',  '1030.0002.0009', 1)

select g.goodId as '@Id'
    , (
        select l.num as '@num'
            , l.description as '@description'
            , (
                select cast(pa.num as int) as '@num'
                    , (
                        select po.pos as '@num'
                        from @MyTable po
                        where g.goodId = po.goodId and po.pos is not null and l.num = parsename(po.docType, 3) and pa.num = parsename(po.docType, 2)
                        for xml path('pos'), type
                    ) as [*]
                from (
                    select distinct parsename(pa.docType, 2) num
                    from @MyTable pa
                    where g.goodId = pa.goodId and pa.pos is not null and l.num = parsename(pa.docType, 3)
                ) pa
                for xml path('part'), type
            ) as [*]
        from (
            select distinct parsename(l.docType, 3) num, l.description
            from @MyTable l
            where g.goodId = l.goodId and l.pos is null
        ) l
        order by l.num
        for xml path('list'), type
    ) as [*]
from (
    select distinct goodId
    from @MyTable
) g
for xml path('good'), type

Answer 2

Don't remember if it's possible to do without heavy nesting like this:

;with cte as (
    select
        goodId, pos, description,
        left(docType, 4) as list_num,
        cast(substring(docType, 6, 4) as int) as part_num,
        left(docType, 9) as full_part_num
    from Table1
)
select
    t1.goodId as Id,
    (
        select
            t2.list_num as num,
            t2.description,
            (
                select
                    t3.part_num as num,
                    (
                        select
                            t4.pos as num
                        from cte as t4
                        where t4.full_part_num = t3.full_part_num
                        for xml raw('pos'), type
                    )
                from cte as t3
                where
                    t3.goodId = t1.goodId and t3.list_num = t2.list_num and
                    t3.pos is not null
                group by t3.part_num, t3.full_part_num
                for xml raw('part'), type
            )
        from cte as t2
        where t2.goodId = t1.goodId and t2.pos is null
        for xml raw('list'), type
    )
from cte as t1
group by t1.goodId
for xml raw('good');

sql fiddle demo