Question

I have the following classes below, I want to return all USLocation classes for a specific state:

var usLocations = (from s in GetUSStates() where s.Code == stateCode select s.Locations);

But I keep getting the error:

Cannot implicitly convert type
‘System.Collections.Generic.IEnumerable<System.Collections.Generic.IEnumerable<A.Model.USLocation>>’
to ‘System.Collections.Generic.List<A.Model.USLocation>’. An explicit
conversion exists (are you missing a cast?)

Seems like the “select s.Locations is returning a collection within a collection. What am I doing wrong here?

public class USState
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Code { get; set; }
    public IEnumerable<USLocation> Locations { get; set; } 
    public override string ToString()
    {
        return string.Format("{0}:{1} ({2})", Name, Code, Id);
    }
}

public class USLocation
{
    public int Id { get; set; }
    public string Name { get; set; }
}

Answer 1

You are selecting collection instead of single item. That’s why usLocation is IEnumerable of IEnumerables. Try using SelectMany and (optionally) ToList:

var usLocations = GetUSStates().Where(s => s.Code == stateCode).SelectMany(s => s.Locations).ToList();

and you’ll get a list of USLocation.