Question

I’m trying to split an SQL results set (in a Stored Proc) into multiple columns for XML formatting. I have a results set with a Supplier Number and a Product Number like this:

SupplierID    ProdCode
-----------   --------- 
Supp1         Prod1
Supp1         Prod2
Supp1         Prod3
Supp2         Prod2
Supp2         Prod3
Supp3         Prod2

etc.

I need to split this results set so that each supplier has its own dataset, which can then be split into its own XML node, as shown here:

<SUPPLIER>
    <SUPPLIER_LINES>
        <SUPPNO>Supp1</SUPPNO>
        <PRODCODE>Prod1</WWPROD>
    </SUPPLIER_LINES>
    <SUPPLIER_LINES>
        <SUPPNO>Supp1</SUPPNO>
        <PRODCODE>Prod2</WWPROD>
    </SUPPLIER_LINES>
    <SUPPLIER_LINES>
        <SUPPNO>Supp1</SUPPNO>
        <PRODCODE>Prod3</WWPROD>
    </SUPPLIER_LINES>
</SUPPLIER>
<SUPPLIER>
    <SUPPLIER_LINES>
        <SUPPNO>Supp2</SUPPNO>
        <PRODCODE>Prod2</WWPROD>
    </SUPPLIER_LINES>
    <SUPPLIER_LINES>
        <SUPPNO>Supp2</SUPPNO>
        <PRODCODE>Prod3</WWPROD>
    </SUPPLIER_LINES>
</SUPPLIER>

I’ll be able to figure out the XML formatting, but am having trouble splitting the results inside a stored proc to get this:

SupplierID  ProdCode
Supp1       Prod1
Supp1       Prod2

SupplierID  ProdCode
Supp2       Prod2
Supp2       Prod3

Answer 1

You can do a group by on SupplierID for the SUPPLIER nodes and use a correlated sub-query to get the SUPPLIER_LINES nodes.

select (
         select T2.SupplierID as SUPNO,
                T2.ProdCode as PRODCODE
         from YourTable as T2
         where T1.SupplierID = T2.SupplierID  
         for xml path('SUPPLIER_LINES'), type
       )
from YourTable as T1
group by SupplierID
for xml path('SUPPLIER')

You probably have suppliers in table of it’s own so if you use that table in the main query you don’t have to do the group by.