CODEWITHSUNDEEP
c#.netjsonlinq
Nate K
Nate K

Reputation: 260

LINQ query for comparing two objects?

I need to return a subset of an object based off of a list of values in another object.

Object to return:

public class Item
{
    public string Title {get;set;}
    public Item subItems {get;set;}
}

I want to select a subset of "Items" based off of the items property on a User table:

public class User
{
    public string ID {get;set;}
    public Subscription[] subscriptions {get;set;}
}

public class Subscription
{
    public string Title {get;set;}
}

So, each User will have an array of subscriptions. I want to return an Item object for a specific user, where the Item Title is in the list of Titles within the user's subscription.

eg...

Items:[
{ title: "USA Today",
  otherdata: "..."},
{ title: "WSJ",
  otherdata: "..."},
{ title: "ET Weekly",
  otherdata: "..."}
]

Users: [
{ ID: "joe schmo",
  subscriptions" : [
    { item : "USA Today" },
    { item : "ET Weekly" }
  ]
}...]

In this example, I want to return :

items = [ {title : "USA Today"
           otherdata: "..."},
          {title: "ET Weekly",
           otherdata: "..."}
        ]

Upvotes: 0

Views: 1518

Answers (1)

Servy
Servy

Reputation: 203837

What you have here is just two operations, one to flatten the sequence of users into the sequence of subscriptsions, and then a Join of the subscriptions with items on the Title property of each:

var query = from user in users
            from subscription in user.subscriptions
            join item in items
            on subscription.Title equals item.Title
            select item;

Upvotes: 2

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