I've written a LINQ query that should return an int value. but I'm not able to convert this value to int and an exception occured:
Unable to cast object of type 'QuickRoutes.DAL.RouteLinq' to type 'System.IConvertible'.
this is my LINQ :
var res = (from p in aspdb.RouteLinqs
orderby p.RouteId descending
select p).Take(1);
and the exception occures here:
route.Id =Convert.ToInt32(res.FirstOrDefault());
how can I solve this problem?
that is because res.FirstOrDefault() returns a RouteLinqs type object, because you are using select p , you may select a field using select p.FieldName, where FieldName is the property you require for conversion, which is probably RouteId
You may want to query the particular field in your linq query.
var res = (from p in aspdb.RouteLinqs
orderby p.RouteId descending
select p.RouteId).Take(1); //p.RouteID or any field you want.
Or with your current query, you may do:
route.Id =Convert.ToInt32(res.FirstOrDefault().RouteID);
Looks like you're selecting the max route id, so why not just do:
route.Id = aspdb.RouteLinqs.Max(x => x.RouteId);
This code should work:
route.Id = Convert.ToInt32((res.FirstOrDefault()).FieldName);
Not sure how your is but RouteLinqs is defined, but perhaps you are looking to select a specific object from the class RouteLinqs.
var res = (from p in aspdb.RouteLinqs
orderby p.RouteId descending
select p.SomeProperty).Take(1);
In this case p is a single item of RouteLinqs and p.SomeProperty should be your int value.
First make linq :
IQueryable<int> query = (from p in aspdb.RouteLinqs
orderby p.RouteId descending
select p.Id);
Than run:
int result = query.FirstOrDefault();
In 1 command:
int result = (from p in aspdb.RouteLinqs
orderby p.RouteId descending
select p.Id).FirstOrDefault();
