Linq Expression problem

[steve]

Hi,

I am trying to do something along the lines of

private static Expression<Func<Customer, string>> CreateSelectorExpression(string propertyName)

    {

        var paramterExpression = Expression.Parameter(typeof(Customer));

        return (Expression<Func<Customer, string>>)Expression.Lambda(Expression.PropertyOrField(paramterExpression, propertyName), paramterExpression);

    }

When using this expression in a linq select against a LinqToEntitiesDomainService works prefectly

When using it against an openaccessdomainservice it fails with a null reference exception.

It took me ages to resolve this but in the end it only took a small change.  Changing

var paramterExpression = Expression.Parameter(typeof(Customer));

to
var paramterExpression = Expression.Parameter(typeof(Customer), "ANYTHING_HERE);

allows the query to run successfuly.  Even putting "Param_0" which is what the first parameter constructor would use internally still works fine.  I thought this 2nd name parameter was purely used for debugging and printing purposes ?

I think I have a fix which is fine but something doesn't feel quite right

Regards

Steve Hayles

[PetarP]

Hi steve,

 Indeed we have an internal problem when translating the Linq query in the way you have originally defined it and the workaround is the one you have employed yourself. There shouldn't be a problem to use the workaround as it does not limit the functionality you are targeting.
We are continually improving our Linq support and we will have that issue in mind. Please find your Telerik points updated for bringing that to our attention.

Best wishes,
Petar
the Telerik team