asked on

Linq Null Problem

When I fetch data from the following Linq query, it errors when it hits a record where the column is null.

Is there a way that I can handle this in the query so that it doesn't throw an exception? (perhaps changing nulls to zero length strings?)

Dim feedbacks = From fb As Object In listIn
            Let member = fb.GetType().GetProperty(groupMember).GetValue(fb).ToString()
            Order By member

Open in new window

kaufmed

Dim feedbacks = From fb As Object In listIn
                Where fb IsNot Nothing
                Let member = fb.GetType().GetProperty(groupMember).GetValue(fb).ToString()
                Order By member

Open in new window

BlueYonder

toString() cannot be used on null values. Add 1 or 2

where !string.IsNullOrEmpty(fb)

where !fb.FieldToCheck.Equals(null)

Dodsworth

ASKER

I still need a record back when the column is null though.

BlueYonder

Remove .ToString()

Dodsworth

ASKER

so I can't change he nulls to zero length?

kaufmed

Which part is throwing the exception?

Dodsworth

ASKER

the .tostring

BlueYonder

update let member to
Let member = fb.GetType().GetProperty(groupMember).GetValue(fb) == null ? "" : fb.GetType().GetProperty(groupMember).GetValue(fb).ToString()

ASKER CERTIFIED SOLUTION

kaufmed

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

BlueYonder

Here is the complete updated statement

Dim feedbacks = From fb As Object In listIn
Let member = fb.GetType().GetProperty(groupMember).GetValue(fb) == null ? "" : fb.GetType().GetProperty(groupMember).GetValue(fb).ToString()
Order By member

kaufmed

@BlueYonder

I don't think C# syntax works in VB ; )

BlueYonder

Sorry, just used to c#. Here's the VB version

Dim feedbacks = From fb As Object In listIn
Let member = If(fb.GetType().GetProperty(groupMember).GetValue(fb) Is Nothing, "", fb.GetType().GetProperty(groupMember).GetValue(fb))
Order By member