Wriju's BLOG

.NET, Cloud and everything

LINQ to XML : Handling blank or no Element and Attribute

It quite so happen that you are working with XML where you are expecting a specific element in every set. But somehow that is missing in some of the sets. Now at runtime you would get an error.. The XML file which I am targeting <?xml version="1.0" encoding="utf-8"?> <Employees> <Employee Location="Earth"> <Name>Wriju</Name> <Email>a@a.com</Email> </Employee> <Employee… Read more

LINQ : From Basics to Query

Many of us are aware of LINQ today. LINQ is an amazing programming language feature. During my discussions I find a lot of myths around understanding. Here I have tried to demonstrate from some basics of C# 3.0 language enhancements to delegate, anonymous type, lambda expression and finally LINQ. How it has evolved. https://channel9.msdn.com/posts/LINQ-Evaluation-From-Basics-to-Implementation Namoskar!!!… Read more

LINQ to SQL : Windows Forms Dynamic Where Clause

While I was reading the book LINQ in Action, I found this chapter. Below is how we can do in LINQ to SQL. The scenario is if you want to create a LINQ and pass the where clause based on user input from UI, you need to write different queries. Instead, how you can do… Read more

Parallel Computing: PLINQ

Visual Studio 2010 has new API for LINQ (Language Integrated Query). This helps us to implement the power of Parallel Computing in declarative manner. LINQ without Parallel Extension It will take 3 sec for 28 thousand elements. static void Main(string[] args) {     Stopwatch sw = Stopwatch.StartNew();         DoIt();       Console.WriteLine(“Elapsed = “… Read more

LINQ to CSV : Getting data the way you want

Getting data from CSV is one of the mostly used business in applications/tools development. Here how we can do it in LINQ, You have a table called Emp with the below details, CREATE TABLE [dbo].[Emp](       [Id] [int] IDENTITY(1,1) NOT NULL,       [FirstName] [varchar](50) NOT NULL,       [LastName] [varchar](50) NULL,  CONSTRAINT [PK_Emp] PRIMARY KEY CLUSTERED… Read more

LINQ to XML : Understanding Annotations

Annotations are used for private use. It does not directly associated and known as Black Box in XML world. This can also be considered as meta tag. Below is an example on how it can be handled. I have created a sample Windows Applications and will try to capture my understanding. /// <summary> /// Class… Read more

LINQ – Uniformity All Over

I have spent a while with LINQ and still feel very new whenever I explore some new power. Here I am going to describe you how LINQ uniformly allows you write for the various types of data.   In-memory data source ++++++++++++++++ List<int> arrInt = new List<int> { 1, 2, 3, 4, 5, 6, 7,… Read more

LINQ to SQL : Understanding Compiled Query

Understanding Compiled Query connects me to my experience in C# 3.0. Based on my personal understanding I am discussing it.   You may be aware of Func<>. And you know it is a flexible delegate which allows you create reusable functions. Exactly the same way we can create compiled query so that we can prevent… Read more

LINQ to SQL : Returning Scalar Value from Stored Procedure

In LINQ to SQL it is not that easy thing to achieve as compared to other features. Let us assume you have a Stored Procedure like, Case 1: With Output Parameter CREATE PROCEDURE [dbo].[GetEmployeeCount]       @OutVal DateTime OUTPUT AS BEGIN       SELECT @OutVal = GetDate() END You need to write code which will look like,… Read more

LINQ to SQL : Using ChangeSet for Audit Trail

Most of the transactional scenario, you may need to add the transaction to some table for ref. many apps does it for admin perspective.   Problem   You can do it in LINQ to SQL with ChangeSet but the problem is with Inserts. It does not give you the Identity field value until and unless… Read more

C# 4.0 : New Extension Method “Zip”

While browsing the features I found an interesting extension method called “Zip”. How it works, let’s check it. List<string> names = new List<string> {“Debajyoti”, “Sumitra”, “Wriju” , “Writam”, “Tupur” };   List<int> ages = new List<int>{ 67, 58, 30, 24, 26 };   var zipped = names.Zip(ages, (name, age) => name + ” is “… Read more

LINQ to Entity : Supported and Unsupported Methods

There is a correction for this Post, so do I have changed the title. Thanks to Chris Love who pointed me the faults with earlier post, I got few question on some of the popular paging methods of LINQ which does not work on LINQ to Entity. This is by design and quite logical. In… Read more

ADO.NET Entity: LINQ to Entity with Relationship

Relationship and getting data from Entity Framework using Northwind database Simple Query   using (NorthwindEntities ctx = new NorthwindEntities()) {     var query = from o in ctx.Orders                 select o.OrderID;       foreach (var k in query)     {         Console.WriteLine(k);     } }   Now if you want to filter this with the… Read more

ADO.NET Entity: Insert Update and Delete with Relationship

Few days back I had written an article on Insert/Update/Delete for simple standalone tables at ADO.NET Entity: Insert Update and Delete. Now after that many of you had requested me to put article on how it works with relationship.   Here I will use a database created by me. There will be two tables connected… Read more

ADO.NET Entity: Insert Update and Delete

For small blogs, it requires more references and explanation, which sometimes are redundant. So I thought of writing single blog which is combination of topics more or less related to one thing.   I am exploring ADO.NET Entity Framework and have been trying things out there. Here I am planning to demonstrate how to do… Read more

LINQ to SQL vs. ADO.NET – A Comparison

ADO.NET is our contemporary data access component and now we have written many applications. Now there has been a lot of talk on LINQ to SQL. So we are little skeptical about this component and trying to find some relation between existing ADO.NET technology.   Purpose of this post is to give some quick brief… Read more

LINQ to SQL : Missing Manual are at MSDN

ADO.NET and LINQ to SQL Describes the relationship of ADO.NET and LINQ to SQL.   Analyzing LINQ to SQL Source Code Describes how to analyze LINQ to SQL mapping by generating and viewing source code from the Northwind sample database.   Customizing Insert, Update, and Delete Operations (LINQ to SQL) Describes how to add validation… Read more

LINQ to Entity : Querying data using ADO.NET Entity Framework

ADO.NET Entity Framework have evolved since we have released it first time. Now with the Visual Studio 2008 if you install the .NET Framework 3.5 SP1 and Visual Studio 2008 SP1 you will get the fully functional version of ADO.NET Entity Framework. This is post Beta 3 release. To create a .edmx file you have… Read more

LINQ to SQL: Making it N-Tier

You can create your application use LINQ to SQL and make it N-Tier. Go ahead and watch out the MSDN Documents N-Tier and Remote Applications with LINQ to SQL LINQ to SQL N-Tier with ASP.NET LINQ to SQL N-Tier with Web Services LINQ to SQL with Tightly-Coupled Client-Server Applications Implementing Business Logic (LINQ to SQL)… Read more

LINQ to XML : Querying XML with Namespaces

This question arises in one of discussions. If you have a XML document with “xmlns” then LINQ to XML does not return any IEnumerable<T> J. This is strange but true for XPath and XQuery. There is a trick to get it done, Let us assume that you have a XML as follows, <?xml version=“1.0“ encoding=“utf-8“?>… Read more

LINQ : IEnumerable<T> and IQueryable<T>

IEnumerable<T> and IQueryable<T> are the two most used terms of any LINQ discussion. What I am trying to here is that I am trying to simplify the two interfaces depending on their behavior. In LINQ world we generally have few providers available within .NET Framework, like LINQ to Object, LINQ to SQL, LINQ to XML…. Read more

LINQ to SQL : FAQ Answer By Matt Warren

Wonderful composition of FAQ is available at http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=2769747&SiteID=1 by Matt Warren.   Q: How do I get default values from the database when inserting new entities? A: LINQ to SQL does not support using default values from the database.  The values in the entity at the time SubmitChanges is called are used instead.  You can… Read more

LINQ to XML : Modifying XML document

You have XML document now you want to modify that XML file using LINQ to XML. It is as easy as you generally modify any database column value.   Let us create a dummy XML stream,   //Create dummy XML to work var root = new XElement(“parent”,     from i in new int[] { 1,… Read more

LINQ to XML : Changing connectionString in app.config

When you create data bind application using wizard in Windows Forms application and connection string gets added to you settings file. Now you may be interested in changing that connection string but problems, 1)     The connection string in settings has an Application Scope so it is ReadOnly property. You modify and remove “ReadOnly” from .vb… Read more

LINQ to XML : Adding Namespace quickly

I have written a post earlier on how to attach Namespaces. After reading my article someone complained about the redundancy of the code. I also realized the pain. I was reading the book C# 3.0 In a Nutshell. There I got a very elegant solution. Let me explain the scenario,   If you create a… Read more

LINQ to XML : Join Xml Data

Let’s say I have created two Xml files using LINQ to XML from Northwind database. I have taken two tables Category and Products and tried to join between two different files.   Category XML   <?xml version=“1.0“ encoding=“utf-8“?> <categories>   <category id=“1“>     <CategoryName>Beverages</CategoryName>   </category>   <category id=“2“>     <CategoryName>Condiments</CategoryName>   </category>   <category… Read more

LINQ to XML : Working with Namespaces

If you are working with complex real world XML then you have to deal with namespaces to disambiguate. There are several ways to implement namespaces in LINQ to XML. One is you can use pure string to add your namespace with each element declaration, like   <root>   <child /> </root>   To create the… Read more

LINQ to SQL Overview Video

Luca, the Microsoft Lead Program Manager, he is one of my favorite presenters. The way he demonstrate uninteresting thing and make fun of himself is one everyone should learn. Please enjoy the through presentation of LINQ to SQL at http://blogs.msdn.com/lucabol/archive/2008/03/03/linq-to-sql-overview-video.aspx   Namoskar!!!… Read more

C# 3.0 Query Expressions by Bruce Eckel and Jamie King

Bruce, a renowned author of the famous book “Thinking in Java” is now exploring C# 3.0. He wrote many other books on Ø       The Hands-On Java Seminar CD ROM (available on the Web site) Ø       Thinking in C++ (PH 1995; 2nd edition 2000, Volume 2 with Chuck Allison, 2003) Ø       C++ Inside & Out (Osborne/McGraw-Hill… Read more

LINQ to XML : Creating XML from another XML

Based on my previous post if I have to filter the list of customers only in the country “US” and create another XML which may look like,   <?xml version=“1.0“ encoding=“utf-8“?> <usaCustomers>   <usaCustomer>     <title>Marketing Manager</title>     <name>Howard Snyder</name>   </usaCustomer>   <usaCustomer>     <title>Sales Representative</title>     <name>Yoshi Latimer</name>   </usaCustomer>   <usaCustomer>    … Read more

LINQ to XML : Creating complex XML through LINQ

We can generate hierarchical object graph in our memory though LINQ. To be more realistic we can bring data from relational database. So if we consider Northwind database and use LINQ to SQL to bring all the Customers and their Orders and Order Details the query would look like,     //LINQ to SQL way… Read more

LINQ to XML : Two important classes XElement and XAttribute

XElement and XAttribute are the two  very important classes available in System.Xml.Linq.dll assembly. Using these two classes you can do lot of things in the LINQ to XML world. I will show you step by step how,   For just an element   XElement _root = new XElement(“root”);   _root.Save(fileName);   And the output will… Read more

LINQ to SQL : Understanding Mapping

In LINQ to SQL you play with pure .NET objects and write your LINQ on top of that. But question might arise how this magic happens. Though we say that it is object, the question might arise in our mind that there has to be a mechanism through which it connects. Yes, there is. That… Read more

Sharing “var” across the method

One of the biggest limitation in “var” is that it cannot be shared across the methods. So if you are doing something using that keyword then you have to stick to the local. I was reading Alex’s Blog where he explained it very nicely,   Here is my implementation,   Create an Extension method  … Read more

LINQ to SQL and ADO.NET

Here I am going to compare the two technologies and point some missing areas.   Let us use the Northwind database and get the list of Customers from city London. The ADO.NET approach would be,   static void Main(string[] args) {     string sConn = @”ConnectionString”;     using (SqlConnection conn = new SqlConnection(sConn))     {… Read more

LINQ to SQL : What is DataContext.Translate Method

DataContext’s Translate method converts existing IDataReader to an IEnumerable<T>. This is very useful when you may need to run raw SQL Query though System.Data.Linq. I am getting few similarities with DataContext’s ExecuteQuery.   How Translate works +++++++++++++ Assuming I am using Northwind database.     using (NWDataContext db = new NWDataContext()) {     DbConnection conn… Read more

C# 3.0 : Joining two in-memory collection through LINQ

LINQ allows us to join different collection source provided we are mapping with two properties with the same type. It is easy, it is quick and it is concise.     //Create Employee Class class Employee {     public int ID { get; set; }     public string Name { get; set; }     public… Read more

LINQ to SQL : Enabling .dbml file for WCF

LINQ to SQL is object relational model and .dbml file generates the class file for all kind of Create, read, update and delete (CRUD) through the mapping mechanism. Ideally this should allow us to enable it for WCF Service. But for that we have to manually add DataContract and DataMember attributes. We can use .dbml’s… Read more

Visual Studio 2008 Training Kit Videos on LINQ

Visual Studio 2008 Training Kit videos are now available on web. Get some real exciting presentations   VS2008 Training Kit: What’s new in C# 3.0? VS2008 Training Kit: What’s new in Visual Basic 9.0? VS2008 Training Kit: .NET Language Integrated Query (LINQ) VS2008 Training Kit: Using LINQ with Relational Data   For more detailed list… Read more

C# 3.0 : Evaluation of Lambda Expression to Language INtegrated Query (LINQ)

From code name “cool” to C# 3.0, it’s been a long journey for this amazing language with .NET Runtime. Here I am going to show you the evaluation step by step.   Let us assume we have generic list of integers and I need to find the even numbers from that list,   List<int> arrInt… Read more

LINQ to SQL: Working with hierarchical data

LINQ to SQL supports hierarchical data and you can easily create a query and get output from there. Let us take an example of Northwind database. Northwind has Category -> Products -> Order_Details tables. -> indicates one to many relationships here. So ideally for a Category can have multiple products and a product can have… Read more

LINQ to SQL : New method DataContext.GetCommand()

LINQ to SQL we can read the generated T_SQL query using DataContext.Log or SQLQueryVisualizer. But If you are working with WebProject the Log property not very much convenient as you have to use TextWriter to dump the generated T-SQL query.   In Orcas Beta 1 we had DataContext.GetQueryText which used to give us the generated… Read more

C# 3.0: Vote for the keyword “var”

You all probably know what is “var”. You might have a question why this new keyword is required in programming language like C#. One of the few strong reasons is to have an Anonymous Type stored in a variable. Whenever you have to initialize a type you have to mention the type before you give… Read more

LINQ to SQL Windows Form Binding Data Step by Step

LINQ to SQL designer in Visual Studio allows us to create mapped class using the drag and drop feature from Server Explorer. Now that is business object which ideally you could use as your datasource and from Visual Studio 2008. So let us have this step by step, Open your Visual Studio 2008 and create… Read more

LINQ to SQL : Some of the best BLOGs

Some of the best blogs on LINQ to SQL I found are available for great learning, Scott Guthrie The Famous LINQ TO SQL Series Part 1: Using LINQ to SQL Part 2: Defining our Data Model Classes Part 3: Querying our Database Part 4: Updating our Database Part 5: Binding UI using the ASP LinqDataSource… Read more

C# 3.0 : Anonymous Type and .NET Reflection Hand-in-Hand

Anonymous Type is nothing but the type which gets defined by CLR (not you). So that type is as rich as any other normal type. Probably the conventional way to find the components of an Anonymous Type through reflection would be clearer to us,   static void Main() {     //Anonymous Type     var anyType… Read more

LINQ to SQL : Change in DataContext from Beta 1 to Beta 2

During the demonstration I have noticed that two major methods of DataContext has changed from Beta 1 to Beta 2.   First one, is the new name for the class DataShape(). Now there is no class called DataShape() but we have DataLoadOptions().     var loadOption = new DataLoadOptions();            loadOption.LoadWith<Customer>(c => c.Orders);   db.LoadOptions =… Read more

LINQ to SQL : Paging Data

When we work with relational database and especially when with larger data we generally go for custom paging. This allows us to create superfast application.   The simple logic for paged query is like,   Let’s suppose you have 100 rows. Now you want to get data of page size 10 for page 2.  … Read more

Have you tried LINQPad (Beta)?

Experiment and learn new concept of LINQ. This is just an exe which requires no extra installation. Pre-requisites Install just .NET Framework 3.5 (minimal impact) Install Visual C# 2008 Express Install the full Visual Studio 2008 Download http://www.albahari.com/LINQPad.exe For more information please visit, http://www.albahari.com/linqpad.html Aha this is from my screen,   Namoskar!!!… Read more

LINQ to SQL : Using Transaction

LINQ to SQL uses optimistic concurrency be default. LINQ to SQL is pure in memory operation, because you normally get the data from database and store them in .NET memory and perform some pure in memory update to those objects and finally when you are done with your modification you give those data back to… Read more

LINQ and C# 3.0 Articles and Samples

LINQ: .NET Language Integrated Query By Don Box, Anders Hejlsberg LINQ to SQL: .NET Language-Integrated Query for Relational Data By Dinesh Kulkarni, Luca Bolognese, Matt Warren, Anders Hejlsberg, Kit George .NET Language-Integrated Query for XML Data By Michael Champion The .NET Standard Query Operators By Anders Hejlsberg, Mads Torgersen Overview of C# 3.0 By Anders… Read more

LINQ to SQL : Object Relational (O/R) Model

LINQ to SQL is pure Object Relational Model introduced by Microsoft. It used mapping mechanism to represent   Relational Components Object Component Table Class Column Property Foreign-key relationship Association   It gets the user input through this object model and gives the translated value to SQL in form of pure T-SQL query and when query… Read more

LINQ to SQL : Caching the query execution

LINQ to SQL executes or generated SQL statement only when you run a foreach statement or you perform to ToList() method to it. If you need to display the output multiple times without executing the real database query, you can store them in memory. This can be done only when you are sure that the… Read more

LINQ to SQL : Deferred and Immediate Loading

LINQ to SQL has support for both deferred and immediate loading. By default it supports deferred loading but you can configure your code to load the data immediately. Let’s consider the Northwind database. As we know the there are two tables Customer and Orders and one customer can have multiple orders. These two tables have… Read more

LINQ to SQL : Writing DML query to perform quick operation

In LINQ to SQL you also can send the DML query to perform the quick database modification.   Caution!!! It is not recommended as it does not support object model so has no compile time checking.   static void Main(string[] args) {     string strConnection = @”Data Source=wriju-orcas\sqlexpress;Initial Catalog=TestDB;”;       TestDB db = new… Read more

LINQ to SQL : Delete data through Object Model

LINQ to SQL support deleting data through object. Continuing with my previous blog on INSERT, let me discuss about the delete method   static void Main(string[] args) {     string strConnection = @”Connection String”;       TestDB db = new TestDB(strConnection);       db.Log = Console.Out;             //Here I am finding the employee with… Read more

LINQ to SQL : Update data through Object Model

LINQ to SQL support updating data through object. Continuing with my previous blog on INSERT, let me discuss about the update method   static void Main(string[] args) {     string strConnection = @”Connection String”;       TestDB db = new TestDB(strConnection);         //Here I am finding the employee with Id 19     var updateQ… Read more

LINQ to SQL support inserting data through object.

LINQ to SQL support inserting data through object.   using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Data.Linq;   namespace Linq2Sql_demo_doc {     /// <summary>     /// Class to represent the SQL Server table     /// Emp     /// Id int     /// Name varchar(50)     /// </summary>    ///     [Table(Name=“Emp”)]     public class… Read more

LINQ to SQL : Executing DML SQL Query

INSERT/DELETE/UPDATE can be performed in LINQ to SQL through normal T-SQL DML queries,   static void Main(string[] args) {     NorthwindDBDataContext db = new NorthwindDBDataContext();   var query = db.ExecuteCommand(“YOUR DML Query”, “Your    Parameter”);       ObjectDumper.Write(query); }   Are you feeling comfortable? Hold on, please try to avoid this as you have better object… Read more

LINQ to SQL : Executing SQL Query

Yes, you can run normal SQL queries in LINQ to SQL. Sample looks like (but not recommended as you do not have statement completion and validation)   static void Main(string[] args) {     NorthwindDBDataContext db = new NorthwindDBDataContext();       var query = db.ExecuteQuery<Customer>(“SELECT * FROM Customers”, “”);       ObjectDumper.Write(query); }   One of… Read more

ADO.NET Entity Framework June 2007 CTP is available

Overview This CTP contains updates to the ADO.NET Entity Framework since the Visual Studio Codename “Orcas” Beta 1 release, including changes in Object Services, Query, Entity Client, and the Entity Data Model Wizard in Visual Studio. Some of the new features include IPOCO, detaching from long-running ObjectContext instances, multiple entity sets per type, support for… Read more

LINQ: Query to SQL, XML and Object and JOIN them

Getting data from SQL, XML and Object and joining them using Language Integrated Query is something you might be looking for. I have created a small application which brings data from SQL Server (table name is Employee), XML (file name is Department.xml) and Object (Generic list containing list of Managers).   My SQL Table Looks… Read more

C# 3.0 and its major design changes for LINQ

C# 3.0 PM Anson Horton discussed about the LINQ and its impact on C# 3.0 covering Lambda Expressions Extension Methods Anonymous Types Implicitly Typed Local Variables Object Initializers Query Expressions Visit the MSDN Magazine article at http://msdn.microsoft.com/msdnmag/issues/07/06/CSharp30/ Namoskar!!!… Read more

Linq Performance

LINQ is powerful, the internal algorithm has got the power for fine tuning and PLinq is in the pipeline. That means if you will have automatic implementation of parallel LINQ for multi-core processors. Two famous quotes from Anders Hejlsberg are   “With PLinq, effectively you write the code the same way, but we arrange for… Read more

Linq: Why and Its Contemporary

Why LINQ (or other components of Linq). One of the major reasons is that to address the mismatch between relational data domain and object domain. Database was more comfortable for developers from SQL world and they were no where in object domain. Please visit Comparing LINQ and Its Contemporaries for more details. Namoskar!!!… Read more

C# 3.0 Enhancements: Expression Trees (recording)

I have discussed about the Expression Trees in my previous blog at C# 3.0 Enhancements: Expression Trees. I have done a small recording on that showing the demo there. I have uploaded that to MSN Soapbox and you can find that here.   Video: CSharp 3.0 Expression Trees    Namoskar!!!… Read more

C# 3.0 Enhancements: Expression Trees

Expression Tree is the feature which enables us to write function which can be complied on-demand basis. It stores the function in form of structured data rather than executable code. Since this is structured we can easily iterate through it anytime. This is easier than finding something in IL.   Let’s suppose if you have… Read more

Linq to Object: Play with OS Component

  Linq not only allows us to work with .NET objects but also gives us the power to play with OS components like EventLog, Registry, Processes etc. If you plan to develop tool which will monitor the system process activities and will notify admin if there is any unpredictable things happening. It is all about… Read more

LINQ to SQL with real life ASP.NET Data Domain

We have talked a lot about LINQ and its power. One of the main reasons behind the LINQ design goal was to enable the unified query like syntax for any kind of structured data.   There is hardly any ASP.NET application which does not deal with data. We can create layered ASP.NET Application using the… Read more

BLinq: Wow and w’s there

  BLinq is Linq integration to ASP.NET Applications which is now available in official ASP.NET website at http://www.asp.net/sandbox/app_blinq.aspx?tabid=62. You can download and install the exe to work with BLinq. BLinq is named keeping in mind that the web world is captured by blog sites and Linq is the core mapping technology behind it.   If… Read more

LINQ Resources

  Let us compile the resources on LINQ Project and its components. To work with LINQ there are two options available for you. One is to install the Orcas CTP from MSDN and the other is with the Visual Studio 2005 install the LINQ May 2006 CTP. I would prefer to use the second option…. Read more

XLinq: Create XML from object using LINQ

  We have seen how to create the XML content from raw data initializing elements and attributes one by one. More realistic approach in the world of application development would be to read the values either from relational database or collection. Let’s use the combined power of LINQ and XLinq to create XML content easily… Read more

XLinq: Beginners Walkthrough

  Let’s play with Linq to XML (aka XLinq). XLinq is different from conventional .NET way to work with XML. Linq to XML is not the replacement it is smarter and superior way to work with XML with Language-INtegrated Query.   Let’s suppose you need to create XML content like   <employees>   <employee age=“28“>… Read more

LINQ in not only for Object Query

  Hello all,   Here we will explore another side of LINQ (Language-INtegrated Query). We all know that LINQ is to query the object (even to the System object). Using the System.Reflection namespace we can get the list of Methods, Fields etc using LINQ Query (with the filter and sort). Lets see one small example… Read more

‘System.Data.TypedTableBaseExtensions.Where<T>(System.Data.TypedTableBase<T>, System.Query.Func<T,bool>)’ cannot be inferred from the usage. Try specifying the type arguments explicitly

  This is first time I am writing a BLOG post with an error messageJ. This error message you will experience while writing code in Orcas Jan CTP. There is no LINQ Windows or LINQ Console Application template available. So no references/namespace directives will be added automatically. If you have installed Orcas Jan CTP and… Read more

LINQ Changes in January CTP (aka December CTP)

  There are some changes happened with LINQ Project with the January CTP. The namespace names like System.Xml.XLinq or System.Query are no more there. Namespaces got changed to System.Data.Linq and System.Xml.Linq.   Other than namespace and api changes lot of .proj file and C# syntax changes have happened.   For detailed information visit Charlie’s BLOG… Read more

DLinq: ADO.NET vNext a lap around

  Today I would like to discuss on the DLinq the natural roadmap to ADO.NET vNext. Little walkthrough, I am going to explore here which I enjoyed a lot during my hands on.   Create LINQ Console application from your Visual Studio 2005.   Go to LINQ installation folder e.g., C:\Program Files\LINQ Preview\Bin. There you… Read more

XLinq : System.Xml.XLinq vs System.Xml

  System.Xml has given the communication power to dot net and XLinq has refined that. It was very nice experience we have explored how to read XML using . NET. Now we are more excited to see how easily we can get the required value with less code (which was one of the philosophies behind… Read more

XLinq for RSS Feed

  RSS 2.0 is popular in the world of BLOGGING. Let’s not discuss about what RSS does but how we can read RSS using XLinq (LINQ for XML). Here I have tried to read the RSS Feed of my BLOG and the URL for the RSS feed is http://blogs.msdn.com/wriju/rss.xml     This simple function pulls out… Read more

LINQ A Journey through Operators [Concat]

  Imagine you have two arrays and you need to join them. Using LINQ it is as simple as mentioned   using System; using System.Collections.Generic; using System.Text; using System.Query; using System.Xml.XLinq; using System.Data.DLinq;   namespace LINQ_Concat {     class Program     {         static void Main(string[] args)         {               char[] alpha1 = {‘A’,‘B’,‘C’,‘D’,‘E’,‘F’,‘G’,‘H’,‘I’};… Read more

C#: Yesterday, Today, and Tomorrow: An Interview with Anders Hejlsberg, Part 2

  A very interesting interview I found on the net. The discussion on C# and LINQ is in the Page 4.   For full conversation please visit here.   Other interviews with Anders   Deep Inside C#: An Interview with Microsoft Chief Architect Anders Hejlsberg   C#: Yesterday, Today, and Tomorrow: An Interview with Anders… Read more

LINQ: Query vs Lambda Expression

  LINQ is not just for the developers who used to write queries for databases but also for the Functional Programmers. So do not worry if you are not very comfortable with SQL kind of queries, we have a very nice option called “Lambda Expression”. Here I am going to demonstrate the scenario for both… Read more

Anders and Chris McConnell on Channel9

  Nice video on future on LINQ and they had a discussion on how it is possible to have api for programmers enabling the functional programming approach with the power of LINQ. Very nice to hear from Anders that LINQ has target for multi-core and mini-core processor.   Watch the video https://channel9.msdn.com/Showpost.aspx?postid=260202   Namoskar  … Read more

LINQ: OfType<T> Query Operator

    LINQ comes with the OfType<T> query operator, through which we can filter the required object type from a heterogeneous array.   Suppose below is the scenario where we have array with various types but will only retrieve the string type. Here we go with ease of life,     using System; using System.Collections.Generic;… Read more

LINQ: GroupBy – “The Wonderland”

      I was going through the document on LINQ Project Overview then got interested to an example there at page 14. The amazing feature of GroupBy, programming will become the communication language one I am sure. We will have lingo, dialects, accent etc. I am excited to share the logic mentioned there (commented… Read more

LINQ: Custom Object Query

Applies To: .NET Framework 3.0, LINQ   Hello all, I have already discussed about the LINQ model architecture and the query process for .NET object in my previous posts. But how about the object written by you? Most of the time we write our own object and return the collection. LINQ is applicable for any… Read more

LINQ: The Philosophy

Applies To: .NET Framework 3.0, LINQ   LINQ (Language INtegrated Query) it is unified programming model for any kind of data in a data-centric application. Be it Database, XML or Object, this uses same query language throughout. This query language or set operation is integrated in the .NET ecosystem as natural expression language. This concept… Read more