Solved

how to get top records using where condition in LINQ

Posted on 2009-04-02
6
1,239 Views
Last Modified: 2013-11-11
my query is

select top(1) * from tablename where col = value.

i need this query in LINQ.i tried in this way

from x in datacontext.tablename.take(1) where col == value select x.

but it's not getting values.

0
Comment
Question by:ravindra333
  • 3
  • 2
6 Comments
 
LVL 1

Accepted Solution

by:
SysPro earned 500 total points
ID: 24048720
Hello,
try this:
datacontext.tablename (x => x.col == value).Take(1);
SysPro
0
 
LVL 21

Expert Comment

by:naspinski
ID: 24049801
You are getting this because you are first 'taking' 1 record, and if it happens NOT to have a col == value (which it most likely will not) then it returns nothing.  You want to take it after like SysPro says.

Here are a few more ways with LINQ to get the same thing (I prefer 5 myself):
var results1 = (from x in datacontext.tablename where x.col == value select x).Take(1);
var results2 = (from x in datacontext.tablename where x.col == value select x).First();
var results3 = (from x in datacontext.tablename where x.col == value select x).Single();
 
//using lambdas (I like this better as it's cleaner looking code)
var results4 = datacontext.tablename.Where(x => x.col == value).Take(1);
var results5 = datacontext.tablename.First(x => x.col == value);
var results6 = datacontext.tablename.Single(x => x.col == value);

Open in new window

0
 
LVL 9

Expert Comment

by:Sreedhar Vengala
ID: 24056850
Try this:
from t in Transactions.Where(t=>t.StockpileID == 2033).Take(1) select t
0
Master Your Team's Linux and Cloud Stack

Come see why top tech companies like Mailchimp and Media Temple use Linux Academy to build their employee training programs.

 
LVL 21

Expert Comment

by:naspinski
ID: 24056896
sree ven, that will not work, you are mixing syntax
0
 
LVL 21

Expert Comment

by:naspinski
ID: 24056899
i apologize, that will work, but why stretch it out to be that long and confusing by mixing syntax?
0
 
LVL 9

Expert Comment

by:Sreedhar Vengala
ID: 24058542
hello naspinski

was just correcting ravindra333's query,
as you said below will work pretty well too:

        var categories = GetCategories();
        List<Category> list = categories .Where(c => c.Name == "Camera").Take(1).ToList();
0

Featured Post

Master Your Team's Linux and Cloud Stack!

The average business loses $13.5M per year to ineffective training (per 1,000 employees). Keep ahead of the competition and combine in-person quality with online cost and flexibility by training with Linux Academy.

Question has a verified solution.

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

IP addresses can be stored in a database in any of several ways.  These ways may vary based on the volume of the data.  I was dealing with quite a large amount of data for user authentication purpose, and needed a way to minimize the storage.   …
Wouldn’t it be nice if you could test whether an element is contained in an array by using a Contains method just like the one available on List objects? Wouldn’t it be good if you could write code like this? (CODE) In .NET 3.5, this is possible…
Nobody understands Phishing better than an anti-spam company. That’s why we are providing Phishing Awareness Training to our customers. According to a report by Verizon, only 3% of targeted users report malicious emails to management. With compan…
In a recent question (https://www.experts-exchange.com/questions/29004105/Run-AutoHotkey-script-directly-from-Notepad.html) here at Experts Exchange, a member asked how to run an AutoHotkey script (.AHK) directly from Notepad++ (aka NPP). This video…

828 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