Using Linq in VB.NET to verify result set is NULL -

i'm trying validate wether or not 2 matching columns exists using linq/vb.net

i believe assuming null result set being returned 'count' value should null, correct?

below code;

    dim crewnumentered = crewnuminput.text     dim crewleadernumentered = crewleadernuminput.text     dim crewnumunique boolean = false      using db new dbclassdatacontext         dim count = (from in db.warrantypercents a.crewleadernum = crewleadernumentered , a.crewnum = crewnumentered select a.warrantypercentsid).tolist         if count nothing             crewnumunique = true         else             'throw error         end if     end using 

the end result want perform action (code not shown) if crewnumunique == true.

but when result set should null, code continuing fill 'something' count.

what can fix this?

edit: realized value of count isn't null instead returning string 'system.collections.generic.list`1[system.int32]'. have no clue going on.

the query return result set when no matching rows found.

the below sets crewnumunique true if there 1 result. if instead want set crewnumunique true when there no results, use 0 in place of 1.

dim result = in db.warrantypercents a.crewleadernum = crewleadernumentered , a.crewnum = crewnumentered dim count integer = result.count if count = 1    crewnumunique = true else    'throw error end if