Getting column values as comma seperated list using XML PATH()

select tc.customerid,stuff((

select ',' + convert(nvarchar(30),tct.Customer_TripId)

from tollplus.TP_Customers tc

inner join tollplus.TP_Customer_Trips tct

on tc.customerid=tct.customerid and tc.customerid=60000252

for xml path('')),1,1,'')as usergroups

from tollplus.TP_Customers tc where tc.customerid=60000252