c# - How to query from the table using group by with EF6? -

i have table below , need query groups roleid values list , put dto. example , expected result below table.

i know should not complex stuff can't figure out how... went through few examples , have found examples deal count of grouped stuff , not list of them.

+----+--------+--------+ | id | userid | roleid | +----+--------+--------+ |  1 | 1      |    1   | +----+--------+--------+ |  2 | 1      |    2   | +----+--------+--------+ | 3  |  2     |    1   | +----+--------+--------+ 

public class userroledto     {         public int userid { get; set; }          public list<int> roleids { get; set; }     } 

expected result:

var res = new list<userroledto>             {                 new userroledto()                 {                     userid = 1,                     roleids = new list<int>() {1, 2}                 },                 new userroledto()                 {                     userid = 2,                     roleids = new list<int>() {1}                 }             }; 

supposing have mapped junction table entity on model, this:

using(var db=new yourcontext()) {     var res= db.userroles.groupby(ur=>ur.userid)                          .select(g=>new userroledto()                                     {                                        userid = g.key,                                       roleids = g.select(us=>us.roleid).tolist()                                     }                                  ).tolist(); }