NullReferenceException using where clause

Question

I have a scenario that I am getting the result properly .But i have to search it in that result.Here is my code.

if(productSearch.Keyword !=null || productSearch.Code!=null)
{
    var key = productSearch.Keyword;
    var cod = productSearch.Code;

    if (productSearch.Code != null)
    {
        var Selected_Result = result.Results.Where(s => s.Code.ToLower().Contains(cod.ToLower())).ToList();                     
        result.Results = Selected_Result;
    }
    else
    {
        var Selected_Result = result.Results.Where(s => s.Keyword.ToLower().Contains(key.ToLower())).ToList();                        
        result.Results = Selected_Result;
    }
}

But it gives following exception :

Object reference not set to an instance of an object on result.Results.Where(s => s.Code.ToLower().Contains(cod.ToLower())).ToList();

I know s => s.Code.ToLower() is coming NULL, but i dont know why, result has records. Thanks in advance.

Looks like one of items in results has Code equal to null — Sergey Berezovskiy
– Sergey Berezovskiy, Commented Dec 4, 2013 at 10:07
productSearch.Code cannot be null.... but are you checking if result is null, more to the point result.code can be null eh. — BLoB
– BLoB, Commented Dec 4, 2013 at 10:11

James · Accepted Answer · 2013-12-04 10:08:03Z

4

If it's null in the query then chances are it's null in the DB. To be on the safe side you can use the null coalescing operator to make sure you have at least something to call ToLower on e.g.

result.Results.Where(s => (s.Code ?? "").ToLower().Contains(cod.ToLower()))
              .ToList();

answered Dec 4, 2013 at 10:08

James

82.4k19 gold badges172 silver badges245 bronze badges

Sign up to request clarification or add additional context in comments.

6 Comments

James Over a year ago

It's a string, it most certainly can be. If you mean it's a non-nullable at the DB side then, yeah, something's probably wrong with your mapping.

Florian Over a year ago

James wouldn't you rather use 'String.Empty'?

EHS Over a year ago

oh thx..I got my mistake.I actually searching in wrong column.

James Over a year ago

@Campl3r pretty sure EF doesn't support String.Empty. Regardless you aren't gaining much by using String.Empty over "" anyway.

Raphaël Althaus Over a year ago

@James EF does accept String.Empty No gain indeed, just a coding choice... I also prefer String.Empty, but have no religion

|

Collectives™ on Stack Overflow

NullReferenceException using where clause

1 Answer 1

6 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

6 Comments

Your Answer

Sign up or log in

Post as a guest

Related