Question

This is my (simplified) code:

Controller

var query = from f in _db.Firms
    where f.Name.ToLower().Contains(search.ToLower()) 
        || f.Keyword.ToLower().Contains(search.ToLower()) 
        || f.KeywordList.ToLower().Contains(search.ToLower())
    select f;

User Model

public class User
{
    [Key]
    public int ID { get; set; }

    public string Username { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }

    public int FirmID { get; set; }
    [ForeignKey("FirmID")] 
    public virtual Firm Firm { get; set; }
}

Firm Model

public class Firm
{
    [Key]
    public int ID { get; set; }

    public string Keyword { get; set; }
    public string KeywordList { get; set; }
    public string Name { get; set; }

    public virtual ICollection<User> Users { get; set; }
}

I have a Controller and a View which does list every Firm and it’s Users from a database, which contains a certain string. This works so far. Now, I also want to list Firms, which contains a User who has a username containing the search string. How can I accomplish that?

My thought was something like this, but it doesn’t work, since the Username isn’t available here:

var query = from f in _db.Firms
    where f.Name.ToLower().Contains(search.ToLower()) 
        || f.Keyword.ToLower().Contains(search.ToLower()) 
        || f.KeywordList.ToLower().Contains(search.ToLower())
        || f.Users.Username.ToLower().Contains(search.ToLower())
    select f;

Answer 1

use a join

from firm in _db.Firms
join user in _db.Users on firm.FirmId equals _db.Firm.FirmId
where f.Name.Equals(...) && user.Name.Equals(...) // any other qualifications
select firm;