Questions tagged [linq]

Language INtegrated Query (LINQ) is a Microsoft .NET Framework component that adds native data querying capabilities to .NET languages.

Filter by
Sorted by
Tagged with
4
votes
0answers
93 views

Repository pattern method implementation with entity framework and C#

I have two entities in my database: Employee and Shift. I want to implement a C# repository pattern method, that given two ...
6
votes
2answers
262 views

c# list object with view model child list

I am trying to build this view model that has a ChildViewModel and this was the only way I was able to get it working. Any advice on how to make this code; cleaner, more effective, just overall better!...
5
votes
3answers
105 views

Creating a CSV stream from an object

I have this code that gets a CSV string from a list of objects where the first row in the string is the object's properties and the rows underneath are the properties values. I then create a ...
2
votes
1answer
48 views

How do I make multithreading in sending large file from FTP to Azure large files faster

Currently, I have a code which downloads a file from FTP to local hard disk. It then uploads a file in chunks to Azure. Finally, it deletes the file from local and ftp. This code is very slow though. ...
5
votes
1answer
85 views

Compare List to Enum Where Contains Any

I have a List that I want to compare to an Enum. If a.Value is found in the Enum we return <...
2
votes
1answer
34 views

Iteration over an XDocument based on some existing elements and conditions

I wrote this piece of code which works as expected: ...
1
vote
1answer
53 views

Filter linq query

Any advice on how to make this code; cleaner, more effective, just overall better! Program has three options that can be passed int NewsId,Year and CategoryId. I collection all the data and then do ...
1
vote
2answers
108 views

Building a Word document containing two different tables

I am trying to generate a Word document with two different tables inside it. For this purpose I have two similar methods where I am passing word document reference and data object and table to the ...
1
vote
2answers
105 views

Protein Translation - Translate RNA sequences into proteins

RNA can be broken into three nucleotide sequences called codons, and then translated to a polypeptide like so: RNA: "AUGUUUUCU" => translates to Codons: <...
4
votes
3answers
257 views
4
votes
3answers
134 views

DistinctCount extension method

Here I go again. I have been finding a fairly common pattern in business logic code. And that pattern looks like this: ...
6
votes
5answers
341 views

Find greatest number in array that is a product of some two elements in the same array

Given an array a, find the greatest number in a that is a product of two elements in a. If there are no two elements in a that can be multiplied to produce another element contained in a, return -1. ...
6
votes
1answer
620 views

Async selector in LINQ

LINQ Select usually works like this: IEnumerable<Task<int>> res = new[] {1,2,3}.Select(async i => i); I would ...
4
votes
2answers
167 views

Big O notation for Reverse String

I have here some methods which reverse string characters. Example if given string is "HELLO", it will returns "OLLEH". Are my big o notation for these approaches correct? And which approach is the ...
6
votes
1answer
102 views

Picking a random neighbouring cell, but only picking previously-visited ones if there aren't any unvisited

I'm creating mazes, and have a Cell class (only relevant code shown)... ...
1
vote
0answers
180 views

SelectAsync With Max Degree Of Parallelism

I have been looking for the best approach to creating an extension method that would give me the ability to select in a linq query using async/await with a max degree of parallelism. I'm aware that ...
2
votes
0answers
62 views

Generic search service to filter entries in lists

I'm in the process of implementing a fully generic service to filter out entries (of any type), which are contained in a ICollection. As it is generic, without any ...
1
vote
0answers
34 views

Getting all descendants IWebElements (using XPath) is too slow in Selenium

Well, I'm working with Selenium to scrap a webpage that has obfuscated class names (example <div class="example-gHJkLM">...)... So I needed to create an ...
1
vote
0answers
86 views

get better performance [closed]

I have this code that works, but I'm sure that it can be done better, any suggestions? ...
2
votes
0answers
87 views

LINQ extensions for sequence comparing

The desired behavior would be: ...
3
votes
1answer
124 views

C# Linq search list within list

I am writing a domino draw game in C# and would like to know if there is a simpler/better way to know the player that has been dealt the highest double bone (where x equals y) and what bone it is: <...
4
votes
3answers
820 views

C# + Linq - grouping objects by frames of time found in the data

A bit of background. In the application I work on there are emails sent to notify users about articles they need to review. Each email+recipient pair is stored in database and may be assigned a ...
18
votes
6answers
6k views

Solving Fizz Buzz using LINQ in C#

The Fizz Buzz challenge is well-known and should not need any explanations, right? I recently got a bit bored and came up with a solution for Fizz Buzz using LINQ and even asynchronous code and a lot ...
12
votes
2answers
1k views

Given an array A[] and a number x, check for pair in A[] with sum as x

LINQ/FP style: Assert.IsTrue(new[] {1,2,3}.AnyPairSum(4)); Where: ...
4
votes
0answers
104 views

Implement Sudoku using LINQ

WiKi and GitHub. Sudoku rules are being checked with the following tests: ...
0
votes
0answers
62 views

GCD Groups with list

We have a list. divide the list element into two groups such that when the product of the numbers of two groups is taken and their GCD is calculated, it came out to be 1. Answer the number of ways in ...
7
votes
2answers
166 views

Iterate only once using LINQ

Funny thing, the following test works: ...
4
votes
1answer
79 views

Paginate IEnumerable<T> sequence

I used the following to split sequence into batches: ...
4
votes
2answers
131 views

Finding which items have at least one common value with other items

I have the following collection : ...
1
vote
1answer
84 views

ASP.NET MVC 5, EF 6 filter performance

I'm creating a filter with Linq in an ASP.NET MVC application. I was hoping I could get some tips on performance enhancements, aside from any possible performance enhancements. I have a few questions:...
7
votes
3answers
2k views

LINQ Extension methods MinBy and MaxBy

LINQ Extension I present a LINQ method ArgBy that returns the item of a sequence that corresponds to the predicate specified. Two additional methods ...
4
votes
2answers
97 views

Reverse Dictionary: Group from child array elements and get its minimum key

Objective I have following array and would like to group by each child and get its smallest Id:- ...
4
votes
2answers
179 views

DropDown tree with search

I fetch a bunch of categories for a DropDown tree, and have to implement search in this dropdown. If there is a match in one of the elements, it should also get all ...
5
votes
1answer
309 views

Make utility using LINQ

Make() takes projects with a list of tuples representing project references in the form of (Dependency, Dependent) and returns ...
6
votes
4answers
2k views

LINQ for generating all possible permutations

Permutate() is supposed to generate all possible permutations of the source sequence: ...
3
votes
1answer
101 views

LINQ for extracting N bottom items (async streams)

source.Bottom(n, x => x) should be the same as well known LINQ source.OrderBy(x => x).Take(n) but is more memory/run-time ...
9
votes
4answers
961 views

Filter search results by multiple filters in one operation

I want to filter search results by multiple filters at once. Is it possible to reduce the number of if statements? My code: ...
1
vote
0answers
234 views

E-Commerce Mock App in Console

I have completed this E-Commerce Mock App in Console C# which I used object to store the data to apply some C# OOP and LINQ techniques. Since it is just a mock version, features are reduced to the ...
17
votes
3answers
2k views

ExactlyOne extension method

I often find in codebases something on the order of if (sprockets.Count() > 0) which is easily replaced with LINQ's ...
5
votes
2answers
126 views

PLINQ code analysis in terms of efficiency of cryptographic hashes generation

I have the following code that I wrote in order to find the correct password by generating hashes out of all possible combinations and comparing each of them with the target. I'm trying to make ...
7
votes
5answers
588 views

Grouping into more groups in one iteration

I had a need to group the same dataset in several groups. So instead of repeatedly query the dataset, I made an extension that could do it once. The caveat is, that the result is materialized in ...
5
votes
3answers
424 views

SkipLast of an IEnumerable<T> - Linq Extension

As my answer to this question, I came up with this solution: ...
2
votes
1answer
130 views

Performance issue with empty lists

Here's my updated version of the problem I posted at Calculating time windows for entities, adding in suggested changes as well as a change I did so that the Reflection is 'cached' in a ...
2
votes
1answer
67 views

Populating dropdown lists, using SQL vs. using expression trees and reflection

I'm working with a large enterprise SQL Server database with dozens of tables that are used mainly as lookups to populate dropdown lists, etc. These tables all follow the convention of having (table)...
3
votes
1answer
524 views

Non brute force algorithm for Birthday Chocolate

Problem: https://www.hackerrank.com/challenges/the-birthday-bar/problem Lily has a chocolate bar that she wants to share it with Ron for his birthday. Each of the squares has an integer on it. She ...
3
votes
0answers
31 views

Configure multiple application features by common criteria

My FeatureSerivce provides only basic APIs, so it is good in dealing with single features. Like I can configure only one feauture at a time: ...
2
votes
2answers
43 views

LINQ queries to generate a report on accrued work time on projects

The following code fetches data from a MySql database to generate a simple report on accrued work time on projects. I've been away from Entity Framework for a while and looking at this code you can ...
0
votes
2answers
325 views

Poker Hand evaluation

I want to evaluate Poker Hands an wrote the following Code: https://dotnetfiddle.net/mxMvq9 Anything wrong / to imporve? ...
6
votes
5answers
506 views

Take N elements from List of Lists

I've come with a solution super tricky for a simple requirement. I think I could solve the problem using LinQ, but I'm not seeing it so clearly at all. What's sure, I'm not comfortable with my code. ...
3
votes
2answers
607 views

Group list into elements with same value

This is my Result class: ...

1
2 3 4 5
12