queries in entity framework - asp.net

Question

i have to fetch those records where cityname like'zipcode' where zipcode is variable and apply conditions
var zipcd = (from u in db.ZipCodes1
where u.CityName.Contains(zipcode) && u.CityType == "D"
select u).ToList().Select(u => new Viewsearch
{
Zipcode = u.ZIPCode,
CityName = u.CityName,
stateabbr = u.StateAbbr
}).Distinct();
Viewsearch vs = (Viewsearch)zipcd;
if (zipcd.Count() > 1)
{
locations = "United States;" + vs.stateabbr + ";" + vs.CityName;
}
else if (locations == "")
{
locations = "United States;" + vs.stateabbr + ";" + vs.CityName;
}
else
{
locations = "United States;" + vs.stateabbr + ";" + vs.CityName + "," + locations;
}
if (zipcd.Count() > 3) is greater than 3
{
locations = locations.Replace(locations, "," + "<br>");
}

Answer 1

The problem is that you're casting an iterator to the type of a single element on the line
ViewSearch vs = (ViewSearch)zipcd.
If you want vs to be a single object, you must call First() or FirstOrDefault() on your collection:
ViewSearch vs = zipcd.First(); // Throws if there are no elements
ViewSearch vs = zipcd.FirstOrDefault(); // null if there are no elements

Answer 2

First of all I would suggest that you download and use the lovely LINQPad not only to run your LINQ queries first but also to learn from it (has a lot of samples that you can run right form there, no more config needed)
for your question:
var zipcd = (
from u in db.ZipCodes1
where u.CityName.Contains(zipcode) && u.CityType == "D"
select new Viewsearch
{
Zipcode = u.ZIPCode,
CityName = u.CityName,
stateabbr = u.StateAbbr
}).Distinct().ToList();
As you can see the query works:

Answer 3

Distinct at the end of your query uses IEqualityComparer, and I'm guessing you haven't defined one for Viewsearch. It would look something like this:
public class ViewsearchComparer : IEqualityComparer<Viewsearch>
{
public bool Equals(Viewsearch vs1, Viewsearch vs2)
{
// Implementation
}
public int GetHashCode(Viewsearch vs)
{
// Implementation
}
}
After you have that defined, you pass it into your distinct call:
.Select(u => new Viewsearch
{
Zipcode = u.ZIPCode,
CityName = u.CityName,
Stateabbr = u.StateAbbr
})
.Distinct(new ViewsearchComparer());