DotNetKicks.com - Stories tagged with LINQ

String Matching in LINQ

Tue, 24 Apr 2012 13:27:58 GMT

Performing simple string equality tests is often not enough when application user convenience is key. Often only a fragment of a string is known to the user, or many of them. Sometimes there is a need to search for a fragment in multiple columns. Which options does OpenAccess and LINQ provide to perform string matching? Into which SQL is the LINQ expression translated?

Difference between SkipWhile and Where in linq

Tue, 17 Apr 2012 13:41:40 GMT

Before some time I have written a blog post about the SkipWhile operator and a reader of my blog asked me that we can do the same thing with Where also but there is a difference between this two. So In this post I am going to explain you difference between those two. Where operator filters a list of collection based on condition. It will filter whole collection while SkipWhile will only skip those elements in list until condition is true and after that it will stop filtering of skipping. Now let's take an example where we can see the difference between Where and SkipWhile. Following is a code for that.

TakeWhile operator in linq

Mon, 16 Apr 2012 09:59:10 GMT

In this post I am going to explain TakeWhile Operator in details. TakeWhile is one of partitioning operator available in Linq. It will take sequence until condition becomes false.

SkipWhile Method in Linq

Mon, 16 Apr 2012 09:59:10 GMT

I have been playing around linq and I have found great method call SkipWhile method. SkipWhile methods skips particular element which matches condition in predicate this can be use full in condition where we need to skip elements on particular condition. So let's take some example. I have written following console application code.

A LINQ Style Range Generator

Sun, 01 Apr 2012 09:48:07 GMT

Language-Integrated Query (LINQ) provides the Enumerable.Range method that generates incrementing sequences of integers. This article describes a similar method that allows the creation of more complex ranges with the repeated application of a function.

Building Expression Evaluator with Expression Trees in C# - Part 3

Wed, 21 Mar 2012 12:15:20 GMT

A third post of a series about building expression evaluator using expression trees in C#. This post adds support for variables using shunting yard algorithm.

Building Expression Evaluator with Expression Trees in C# - Part 3

Wed, 21 Mar 2012 12:15:20 GMT

A third post of a series about building expression evaluator using expression trees in C#. This post adds support for variables using shunting yard algorithm.

Building Expression Evaluator with Expression Trees in C# - Part 3

Wed, 21 Mar 2012 12:15:20 GMT

A third post of a series about building expression evaluator using expression trees in C#. This post adds support for variables using shunting yard algorithm.

LOLCode Parser

Wed, 21 Mar 2012 23:37:06 GMT

LOLCode parser and compiler. Now your cat can code for you.

Multiple where clauses in Linq

Fri, 09 Mar 2012 13:56:24 GMT

This might be common knowledge but I discovered today, that you can have as many where clauses in Linq as you like. Makes a Linq query look even cleaner (IMHO).

Build a mvc ajax application using javascript and knockout.js/mvvm

Wed, 22 Feb 2012 19:43:28 GMT

javascriptiqueryable: Javascript to IQueryable is a framework that allows you to write a simple query in javascript client side and then execute it server side with EntityFramework or a linq provider that implement IQueryable. On the server is used "Dynamic Expressions and Queries in LINQ by Microsoft" to compose dynamically your query. There is also support for knockout, so you can use in your pages the "MVVM" pattern. There is also support for jquery mobile, so you can create a datasource for a jquery mobile apps.

Add a visual Linq expression builder to your app today!

Fri, 03 Feb 2012 23:44:34 GMT

Rabb Moshe Plotkin has created and open-sourced a control for creating Linq queries visually. Using this control, you can give your users the power to query data, rather than writing canned reports or queries.

DevForce LINQPad driver

Wed, 18 Jan 2012 06:14:26 GMT

LINQPad is an enormously helpful development tool for building and executing LINQ queries and C#/VB expressions. In response to customer requests, we've built a DevForce LINQPad driver that lets you use LINQPad with DevForce models. There's no need to struggle with the EF or Universal drivers or add namespaces and assemblies.

A Generic Equality Comparer for LINQ

Tue, 17 Jan 2012 14:26:20 GMT

LINQ operators generally use lambda expressions to control their processing and output. Some operators use IEqualityComparer<T> implementations to compare values. This article describes a generic comparer, driven by delegates, designed for use in queries.

Shuffle in linq (part 2)

Sat, 14 Jan 2012 12:51:32 GMT

There are many times when we need to randomly sort a list or array.

Shuffle in Linq

Sat, 14 Jan 2012 02:26:46 GMT

A simple implementation for shuffling a list in linq.

Monadic Philosophy Part 2 - The LINQ Monad

Fri, 06 Jan 2012 14:40:27 GMT

If you don't come from a math or philosophy background (and I don't) "monad" sounds like a made-up word. Of course, understanding OO's use of terms like "class" and "object" can be hard to grok at first too. But at least those terms have some grounding in real-world concepts that non-math geeks come across. Because I couldn't draw an analogy of monads to anything at first, it made grasping the concept of monads very hard for me.

Sequence contains no elements : LINQ error

Fri, 16 Dec 2011 02:33:10 GMT

Learn how to fix linq and lambda expression error "Sequence contains no elements"

Seeing the SQL Generated by LINQ to Entity Queries -- Visual Studio Ma

Mon, 12 Dec 2011 16:03:46 GMT

Sometimes you really, really, really want to see the SQL that LINQ generates when working with the Entity Framework. There is a really simple way to do this using the immediate window that does not involve installing a profiler.

I've Left Query Analyzer Hell for LINQPad Heaven

Thu, 08 Dec 2011 00:55:13 GMT

extensions for linqpad

Architecting Your Data Access Layer with the Entity Framework

Sat, 03 Dec 2011 03:32:25 GMT

I had the pleasure to co-present with one of my fellow evangelists, Dave Bost, on architecting and developing with the ADO.NET Entity Framework this week. I focused on application architecture topics while Dave focused on developing applications.

[WPF] Using Linq to shape data in a CollectionView

Wed, 30 Nov 2011 14:24:54 GMT

This article describes a way to use Linq to specify the filter, sort and grouping of a WPF CollectionView.

LINQ Pitfalls: Using external variables in projections

Mon, 14 Nov 2011 19:57:20 GMT

One issue with NHibernate.Linq provider that surprised me a lot is about variables (or constants) that appear in Select expressions. It seems that you can use it, but once only! Otherwise you'll experience pretty nasty silent fail.

NHibernate.Linq Pitfalls: Order of operators

Sat, 05 Nov 2011 10:47:55 GMT

When writing SQL queries you need to put all the clauses in particular order that is enforced by the SQL language itself and somehow relates with how the RDBMS is going to process the query. When writing NHibernate's LINQ queries, the rules generally still apply.

entity framework a super dataset

Fri, 04 Nov 2011 15:24:27 GMT

Is entity framework a super dataset?