How do you write a conditional sum in SQL XML summing one node value based off another?

Im trying to figure out how to write a conditional sum in SQL XML based on another node in this case when type is 'L' then sum only those days.

Does any know the syntax for that?

<root>
<legs>
     <item>
      <LegDto>
        <type>L</type>
        <cost>15000</cost>
        <days>2</days>
     </LegDto>
    </item>
<legs>
<root>

SELECT b.VoyageResultID,
       b.VoyageID, 
	   c.VoyageObjectXML.value('sum(root/legs/item/LegDto/days)', 'numeric(28,17)') as Portdays,  -- The straight sum works fine
          c.VoyageObjectXML.value('sum(root/legs/item/LegDto/days)', 'numeric(28,17)') as Portdays,  -- SUM only if (root/legs/item/LegDto/type) = 'L' 


	   b.IsActive
FROM [dbo].[tblVoyage] a 
JOIN [dbo].[tblVoyageResult] b ON b.VoyageID = a.VoyageID 
CROSS APPLY (SELECT CONVERT(XML,cc.VoyageObject) AS VoyageObjectXML 
             FROM [dbo].[tblVesselVoyageResultXML] cc 
			 WHERE cc.VoyageResultID = b.VoyageResultID) c
ORDER BY b.VoyageID,b.VoyageResultID,b.IsActive

Select allOpen in new window