c# - LINQ GroupBy 3 properties? -

i've got following class:

public class productinventory : entity {     public virtual product product { get; set; }     public datetime expirationdate { get; set; }     public manager manager { get; set; } } 

and class used in viewmodels looks so:

 public class productinventorycountmodel {     public product product { get; set; }     public datetime expirationdate { get; set; }     public int count { get; set; } } 

i want output of dictionary<manager, list<productinventorycountmodel> displays products manager , expiration date can print out actual data looking this:

managerbob   --producta, expires 8/15/13, count: 10  --producta, expires 10/10/13, count: 40  --productb, expires 6/13/13, count: 30  managertim   --producta, expires 10/10/13, count: 5  --productb, expires 5/25/13, count: 10  --productb, expires 6/13/13, count 40 

how write query in linq when starting list of productinventory? tried using multiple .groupby didn't work.

you stated want dictionary<manager, list<productinventorycountmodel>>, think you'd have this:

var dictionary =      db.productinventory.groupby(x => new { x.manager, x.product, x.expirationdate })       .todictionary(g => g.key.manager,                     g => g.select(x => new productinventorycountmodel                                    {                                       product = x.key.product,                                       expirationdate = x.key.expirationdate,                                       count = x.count()                                   }).tolist());