How to blend an if-else into linq query syntax statement

Question

I have two collections. A collection of Notifications and a collection of Document types. I need to collect information about the both of them and add an extra field depending on something as well. However, I don't have a clue how to do this.

I get the document type ID and name from the Document types collection. And I get only a document type ID from the Notifications collection. If an ID is there in both, there should be an extra field added to the return that is a string value of simply "Subscribed". If not, the string value should be "Unsubscribed". I could work with a bool value as well of course.

This is what I got so far.

Code to get what I need from the notifications:

var notifications = from n in repository.Get<Domain.Notification>()
                                where n.UserId == userID
                                select n.DocTypeId;

Code to get what I need from the document types:

(Note: if I can do the join right here, I would prefer that.)

var doctypes =  from d in repository.Get<Domain.DocumentType>()
                where d.SupplierID == SuppId
                select new { d.Id, d.Name};

What I don't have yet is the join. I don't know how I can add a field to the select new, as it keeps giving me errors when I do. And I don't know how I can do a sort of if-else statement in the Query syntax. I know I once did that in TSQL, so I was hoping it is possible in linq as well.

Code that I have tried but 'feels' wrong to me:

string temp = "unsubscribed";
            bool temp2 = true;
            var testing =
                from d in repository.Get<Domain.DocumentType>()
                where d.SupplierID == SuppId
                select new { d.Id, d.Name, temp, temp2 = false };

So here I tried some things out to get a third field added. It feels somewhat dirty to me as how I did it, but if there is no alternative I'll use this. What I need now is how I can add the if-else part. I know how to do a multiplefrom select, but just not how to do the if-else part.

EDIT

What is inside the two collections:

Document types:

ID
Name
SuppID
Other irrelevant stuff

Notification:

ID
DocTypeID
UserID
Other irrelevant stuff

What I would like as an output:

A list that has three items per object, namely:

Documentype ID
Documenttype name
Bool value (true if the doctype ID was there in the notifications collection, false if not)

Can you show the entity structure with some sample data and out-put that you need — jitender, Apr 04 '17 at 07:02

score 1 · Accepted Answer · answered Apr 04 '17 at 07:35

1

             var notifications = from n in repository.Get<Domain.Notification>()
                            where n.UserId == userID
                            select n.DocTypeId;

             var docTypes = repository.Get<Domain.DocumentType>().Where(d =>d.SupplierID == SuppId).Select(d =>new {
             d.Id,
             d.Name,
             hasEntryInNotifications=notifications.Any(n => n ==d.Id)
             })

answered Apr 04 '17 at 07:35

jitender

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Thanks, I think this will do the trick. I'm going to test it now, if it works I'll come back and check your answer :) – Robin Apr 04 '17 at 07:58
@Robin Ok revert if get any problem else mark it as answer if do the trick – jitender Apr 04 '17 at 09:26

How to blend an if-else into linq query syntax statement

1 Answers1