c# - Join multiple Table Values Into a String -

i have query built c# program produce csv (a pick list warehouse), need extend files functionality , add column in lists items bundled main product. bundled items information across 2 tables.

here main query have:

select  si.itemnumber,         si.itemtitle,         ooi.nqty      open_orderitem ooi         inner join stockitem si on si.pkstockitemid=ooi.fkstockitemid 

i need add column list itemnumbers of linkstockitemid each 1 ideally listed comma separating them , quantity

the table links main current query on pkstockitemid result pklinkstockitemid listed comma seperated

image of tables below simple cant seem head around of information have found on web know basic sql , awesome thank in advance!

tables