web api function throwing exception of System.InvalidOperationException

Question

I am calling the below code in my api from a mobile device and from a Rest client:

[HttpGet]
        [Route("api/mobile/GetUsersList")]
        public IHttpActionResult GetUsersList()
        {

            var users = from c in db.Users
                            select new { c.id, c.user_name, c.reports_to };


            return Ok(users.ToList());

        }

I get an error of:

The cast to value type 'System.Int32' failed because the materialized value is null. Either the result type's generic parameter or the query must use a nullable type

I am not using a where so I'm not sure why this simple query would throw this error.

I am testing the Http GET to this function using Advanced Rest Client.

I see in other SO posts that this error gets thrown when a where parameter is null.

Ryan

Answer 1

Try to specify name directly with cast

var users = from c in db.Users
            select new { id= (int?)c.id, user_name = c.user_name, reports_to = c.reports_to };

or

id = c.id ?? 0