Linq, combining multiple records into comma separated string, grouped by distinct value

Question

I'm trying to do a groupby distinct, then build a csv string:

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[FROM] is a one-to-many join:

        var allCustomerRoles = (from cr in Customers
                                join r in CustomerRoles
                                on cr.Role_ID equals r.Role_ID
                                select new { cr.Customer_No_, r.Role_ID });

So the question is, can you please show me how to write the LINQ query to arrive at the [TO] structure, where Customer_No_ is distinct and it's Role_ID values are concatenated into a CSV string.

Could you explain in detail what problem you are experiencing? — Andrew Barber, Apr 21 '14 at 16:59
My apologies, I should have been more descriptive, edited original post. — Joe C, Apr 21 '14 at 17:02
This link can probalby help you : http://stackoverflow.com/questions/7325278/group-by-in-linq — Réda Mattar, Apr 21 '14 at 17:08
@Réda Mattar, that's it! I knew the answer was out there somewhere...thank you so much! — Joe C, Apr 21 '14 at 17:24

score 6 · Accepted Answer · answered Apr 21 '14 at 17:26

6

Thank you @reda-mattar, your link led me to the solution, here's what I was looking for:

var allCustomerRoles = (from cr in Customers
                        join r in Roles
                        on cr.Role_ID equals r.Role_ID
                        group r.Role_ID by cr.Customer_No_ into g
                        select new { Customer_No_ = g.Key, Role_ID = string.Join(",", g.ToArray()) });

answered Apr 21 '14 at 17:26

Joe C

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@Joe C that really helped – VikrantMore Dec 22 '16 at 07:58

Linq, combining multiple records into comma separated string, grouped by distinct value

1 Answers1