?
Solved

Compare 2 collections

Posted on 2009-05-12
4
Medium Priority
?
635 Views
Last Modified: 2012-05-06
I have 2 collections I want to compare. The collections contains the same objects, but it is sorted different based on a input date:

//Get the collection based on date:
ItemCollection ItemCollection_1 = ItemHandler.GetItems(05/05/2009);
ItemCollection ItemCollection_2 = ItemHandler.GetItems(05/12/2009);


//Here is how I bind the collection to a DataGrid:
this.dtgList.DataSource = ItemCollection_2;
this.dtgList.DataBind();


Example ItemCollection_1 (5th of May):

Id Title  Score
1  hi      30
2  hello  20
3  test   10


Example ItemCollection_2 (12th of May):

Id Title  Score
1  test   50
2  hi       20
3  hello  10


What I need to do is to show "yes" or "no" in the datagrid (make a column called "Increase") if the score is highter or lower than the score last week (ItemCollection_1).
0
Comment
Question by:webressurs
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
4 Comments
 
LVL 3

Assisted Solution

by:demi-os
demi-os earned 2000 total points
ID: 24366242
Please notice that i didnt tested it but it should work.

Assuming you added a column for your increased results to dtgList and your ItemCollection has items like:
 
public class ItemData
{
    public string Id { get; set; }
    public string Title { get; set; }
    public string Score { get; set; }
    public string Increase { get; set; }
}
// this will find, compare and update your ItemCollection_2
foreach (ItemData _item in ItemCollection_2)
{
    ItemData _olditem = ItemCollection_1.Single(s => s.Category.Equals(_item.Title));
    if ((_item.Title == _olditem.Title) && (_item.Score > _olditem.Score)) 
        _item.Increase = "yes"; 
    else
        _item.Increase = "no"; 
}

Open in new window

0
 
LVL 3

Accepted Solution

by:
demi-os earned 2000 total points
ID: 24366573
It looks like i forgot to check if it has the same title at
line 17:  _item.Increase = "no";
should be replaced with:
if (_item.Title == _olditem.Title)  _item.Increase = "no";
foreach (ItemData _item in ItemCollection_2)
{
    ItemData _olditem = ItemCollection_1.Single(s => s.Category.Equals(_item.Title));
    if ((_item.Title == _olditem.Title) && (_item.Score > _olditem.Score)) 
        _item.Increase = "yes"; 
    else
        if (_item.Title == _olditem.Title) _item.Increase = "no";
}

Open in new window

0
 
LVL 1

Author Comment

by:webressurs
ID: 24374180
Hi! I tried to use your code, but dont understand the ".Single" property (ItemCollection_1.Single)? It dont exist...?

I fixed it by using a Dictionary like this:

ItemCollection ItemCollection = ItemHandler.GetItems(05/07/2009);
ItemCollection ItemCollectionCompare = ItemHandler.GetItems(05/01/2009);

Dictionary<int, int> oldItem = new Dictionary<int, int>();

foreach (Item item in ItemCollectionCompare)
{
    oldItem.Add(item.Id, item.Score);
}

ItemCollection newItems = new ItemCollection();
foreach (Item item in ItemCollection)
{
    Item newItem = new Item();

    newItem.Id = item.Id;
    newItem.Title = item.Title;
    newItem.Text = item.Text;
    newItem.Score = item.Score;


    //New list

        if (item.Score < oldItem[item.Id])
        {
            newItem.Result = "Down";
        }
        else if (oldItem[item.Id] == item.Score)
        {
            newItem.Result = "Same";
        }
        else
        {
            newItem.Result = "Up";
        }


    newItems.add(newItem);      

}

this.dtgList.DataSource = newItems;
0
 
LVL 3

Assisted Solution

by:demi-os
demi-os earned 2000 total points
ID: 24375282
I am glad you found a solution.
Single is a method from System.Linq namespace:
http://msdn.microsoft.com/en-us/library/system.linq.enumerable.single.aspx
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Today is the age of broadband.  More and more people are going this route determined to experience the web and it’s multitude of services as quickly and painlessly as possible. Coupled with the move to broadband, people are experiencing the web via …
Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
Monitoring a network: how to monitor network services and why? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the philosophy behind service monitoring and why a handshake validation is critical in network monitoring. Software utilized …
This tutorial will teach you the special effect of super speed similar to the fictional character Wally West aka "The Flash" After Shake : http://www.videocopilot.net/presets/after_shake/ All lightning effects with instructions : http://www.mediaf…

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question