CODEWITHSUNDEEP
c#vb.netlinqlinq-to-entities
ddieppa
ddieppa

Reputation: 6356

merge items into one that are repeated in the same list

I have a query in the database that returns me a list of objects( in my case notifications), but that list brings a lot of repeated items(a notification can contain multiples attachments, so what the query does is a join with the attachment table, bringing back a lot of notificationid repeated, a notification with a lot of attachment). So what i want to acomplish is merge all the attachments for one specific notification id into one item (let say that my notification class has a list of attachments) I did this:

Dim dupes = list.GroupBy(Function(x) x.Notification.NotifiedID)
                .Select(Function(s) s.ToList())
                .ToList()

but i don't know how to merge the grouped ones, any help here?

Upvotes: 0

Views: 992

Answers (2)

Rick Love
Rick Love

Reputation: 12780

After grouping, then select the first from each group:

var firstNotifiedItems = list.GroupBy(x=> x.Notification.NotifiedID).Select(g=> g.First()).ToList();

This will give you a single item for each notifiedID.

However, if you want all the items in a new object:

var notifiedItems = list.GroupBy(x=> x.Notification.NotifiedID).Select(g=> new{NotifiedID=g.First().NotifiedID, Items=g.ToList()}).ToList();

This will give you an object with the NotifiedID and a list of items for that ID.

Upvotes: 1

slash shogdhe
slash shogdhe

Reputation: 4187

Try this in c#

list.GroupBy(x=> x.Notification.NotifiedID).SelectMany(o=> o);

I don't know VB But you can try this

Dim dupes = list.GroupBy(Function(x) x.Notification.NotifiedID)
                .SelectMany(Function(s) s)
                .ToList()

Upvotes: 1

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