c# - Linq expression to filter an a list of entity's collection, and maintain list of entities -

lets have:

public class foo {     public long id { get; set; }     public string name { get; set; }     public icollection<bar> { get; set; } }  public class bar {     public long id { get; set; }     public int age { get; set; }      public virtual foo { get; set; }     public long fooid  { get; set; } } 

our data may this: (assume list<foo>)

// forget syntax, demonstrate data foo[0] = new foo{ id = 1, name = "a", bar = { collection of bars ages on 10 }}; foo[1] = new foo{ id = 2, name = "b", bar = { collection of bars ages on 20 }}; foo[2] = new foo{ id = 3, name = "c", bar = { collection of bars ages under 10 }}; 

now, lets wanted foos bars including bar age between 5-25.

for this, work in reverse , bars, associated foos bars, , re-map bars foo. seems overly complicated should be.

to more clear - all foos bars ages between 5 , 25 :)

if want select foo's , bar's between age of 5 , 25:

var results =      f in db.foos     select new     {         f.id,         f.name,         bars = f.bars.where(b => b.age >= 5 && b.age <= 25)     }; 

this produce anonymous type result. if need create named type (for example if need return result function list<t>) should create simple named type result set:

public class foowithfilteredbarresult // replace whatever name {     public long id { get; set; }     public string name { get; set; }     public ienumerable<bar> { get; set; } }   list<foowithfilteredbarresult> results =      (from f in db.foos      select new foowithfilteredbarresult       {          id = f.id,          name = f.name,          bars = f.bars.where(b => b.age >= 5 && b.age <= 25)      })     .tolist();