validate search result using Linq

I have a search result from the database,

int searchTerm = "xx"

var result = from orderLines in context.OrderLineSearch(searchTerm)
                                    sele开发者_开发技巧ct new
                                    {
                                        OrderNumber = orders.OrderNumber,
                                        OrderLineId = orders.OrderLineId
                                    }; 

I need to validate whether result contains many orders. That is I need to check whether multiple orders are returned or not.

I did the validation by storing the first order number in a variable and compared whether all the other rows contains only this order number. See below

string orderNumber = result.First().OrderNumber;

bool isValid = result.Where(x => x.OrderNumber != orderNumber).Count() == 0;

I want to know the best way to validate using LINQ? Can any one help me?

Thanks in advance.

---

May be you should to try group results by OrderNumber and then calculate Count?

var result = from orderLines in context.OrderLineSearch(searchTerm)
             group orderLines by orderLines.OrderNumber into g   
             select g.Key     
bool hasElements = result.Any();