How to use sub query in CAML in splist

Question

hi,
want to know whether any sub query functionality can be achieved in splist/sp doc lib using  CAML designer 2013/ query builder. also inner joins need to be implemented as pe rmy requirement.
if caml designer is not supported, whats the allternative way of doing this?
can LINQ to SP be used? if yes, can anyone pls roivde how to implement  the same
 help is appreciated

Answer 1

You can use the let keyword to scope a variable containing the result of your subquery.
 However, it depends on the LINQ provider as to whether or not it can understand the command.
For example, you can create the sample like this
var result = (from p in productInQuery
      join o in orderInfoQuery on p.refNo equals o.refNo
      join t in productOutQuery on p.no equals t.productInNo into productIn
      from t in productIn.DefaultIfEmpty()
      let dateOut = (from m in orderInfoQuery where m.refNo == t.refNo select m.processData).FirstOrDefault()
      orderby o.processDate descending
      select new
          modelNo = x.modelNo,
          qty = p.qty,
          dateIn = o.processDate,
          dateOut = dateOut
https://www.youtube.com/watch?v=N3K0h6GDwW4
For more info, check this
http://msdn.microsoft.com/en-us/library/ee539975.aspx