Solved

extracting fields from my lambda expression

Posted on 2012-03-29
6
276 Views
Last Modified: 2012-03-29
I have the following line of code in a function in my unit of work:
Customer c = Customers.FindWhere(x => x.Username == username).FirstOrDefault();

Open in new window


The function that this code is in however simply wants to return the "ID" field of the customer.

Instead of asking for all the customer fields, is there a way of just saying give me the id field?

The generic function .findwhere is using e.f 4.1
0
Comment
Question by:scm0sml
[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
  • 3
6 Comments
 
LVL 75

Expert Comment

by:käµfm³d 👽
ID: 37784432
If I'm understanding the issue correctly, then I think you can use:

var c = Customers.FindWhere(x => x.Username == username).Select(x => x.ID).FirstOrDefault();

Open in new window

0
 

Author Comment

by:scm0sml
ID: 37784446
I was thinking that but I get cannot implicitly convert type int to customer...?
0
 
LVL 75

Accepted Solution

by:
käµfm³d   👽 earned 500 total points
ID: 37784498
Yes, I had to change "Customer c" to "var c" because I wasn't sure what the type of "ID" was. You say that the function "wants to return the 'ID' field of the customer", so I expected that you have specified your function's return value to match the type of "ID"--which in this case seems to be int. The var I used should take care of any typing issues, but you can replace it with int if it makes you more comfortable.
0
Creating Instructional Tutorials  

For Any Use & On Any Platform

Contextual Guidance at the moment of need helps your employees/users adopt software o& achieve even the most complex tasks instantly. Boost knowledge retention, software adoption & employee engagement with easy solution.

 

Author Comment

by:scm0sml
ID: 37784508
ah right i think where i was getting confused was i though the select was just saying populate the id field of the returned customer object as opposed to just returning an int.

That works for me in this case.

If I did want to return say 3 of the 10 fields, could I do that using the lambda?
0
 
LVL 75

Expert Comment

by:käµfm³d 👽
ID: 37784524
Sure:

var c = Customers.FindWhere(x => x.Username == username)
                 .Select(x => new Customer()
                              {
                                  ID = x.ID,
                                  FName = x.FName,
                                  LName = x.LName,
                              })
                 .FirstOrDefault();

Open in new window

0
 

Author Comment

by:scm0sml
ID: 37784629
ah ha...

good man.
0

Featured Post

SharePoint Admin?

Enable Your Employees To Focus On The Core With Intuitive Onscreen Guidance That is With You At The Moment of Need.

Question has a verified solution.

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

Introduction Hi all and welcome to my first article on Experts Exchange. A while ago, someone asked me if i could do some tutorials on object oriented programming. I decided to do them on C#. Now you may ask me, why's that? Well, one of the re…
Introduction This article shows how to use the open source plupload control to upload multiple images. The images are resized on the client side before uploading and the upload is done in chunks. Background I had to provide a way for user…
NetCrunch network monitor is a highly extensive platform for network monitoring and alert generation. In this video you'll see a live demo of NetCrunch with most notable features explained in a walk-through manner. You'll also get to know the philos…
Michael from AdRem Software outlines event notifications and Automatic Corrective Actions in network monitoring. Automatic Corrective Actions are scripts, which can automatically run upon discovery of a certain undesirable condition in your network.…
Suggested Courses

624 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