c# - validate search result using Linq -

i have search result database,

int searchterm = "xx"  var result = orderlines in context.orderlinesearch(searchterm)                                     select new                                     {                                         ordernumber = orders.ordernumber,                                         orderlineid = orders.orderlineid                                     };  

i need validate whether result contains many orders. need check whether multiple orders returned or not.

i did validation storing first order number in variable , compared whether other rows contains order number. see below

string ordernumber = result.first().ordernumber;  bool isvalid = result.where(x => x.ordernumber != ordernumber).count() == 0; 

i want know best way validate using linq? can 1 me?

thanks in advance.

may should try group results ordernumber , calculate count?

var result = orderlines in context.orderlinesearch(searchterm)              group orderlines orderlines.ordernumber g                 select g.key      bool haselements = result.any();