Learn Linq Step By Step

LINQ is language integrated query. Below are simple example of LINQ expression and syntax. We will query an array of string.

All above chapters are enough for beginners to learn and understand Linq query.

Apart from above examples. I recommend you to download LinqPAD. It’s third party free software tool. You can write Linq query and see underlined SQL statements generated by your Linq query.

//Create an array of Strings

string[] arr = "A,B,C,D,E,F,U,X,Y,Z".Split(",".ToCharArray()); 
//Populate listbox with array of strings

ListBox1.DataSource = arr; 

//Bind array of strings to Listbox

ListBox1.DataBind(); 


//Using linq syntex we will query an array of strings and find the word "S"  and "M"

var query = from alphabet in arr 
                    where (alphabet == "S" || alphabet == "M") 

                    select alphabet  ;  
                   // A query body must end with a select clause or a group clause 



foreach(var alpha in query) 
{ 

Response.Write(alpha+" ");   //Write the word found.

}

Linq Where extension.

System.Linq.Enumerable has a extension method called where.


  (new[] {"Ram", "Sham", "Gopal","Mahesh"} ).Where (n => n.Length >= 4)

Output

Sham
 
Gopal
 
Mahesh

Inside of the where expression you can see "n => n.Length >=4", It is read as "n goes to n.length greater than or equal to 4". The operator => is read as "Goes to". It's a lambda expression. We are expecting to get result of array containing elements with length greater than or equal to 4.

Tags:

Linq Group By Multiple Columns Linq group by It’s a very simple example of Linq Group by clause. We are selecting rows from Orders table and grouping orders by shipment city fields. It also ...ASp.net 2.0 step by step Membership Provider ASP.Net Membership provder step by step. Create user, Add user into Role, Authorize user, Redirect user to login. Password recovery control,asp.net membership ...Linq Split String To List Here we will see how to split string to list and display each words using Linq query. Example uses C#.net language. Linq Chapter 1 – Split string to list ...Linq Inner Join Here is very simple inner join example using Linq query expression. We will Inner join Order Table and Order Details table. North wind database contains Ord...Linq Distinct List You want to see how to execute distinct query using Linq expression. Here are example in C#.net which shows stores distinct records in list. Let’s see how to r...Linq Get Duplicate Count Of Words From String Let’s see how to get duplicate words from string using Linq group by syntax. In upcoming chapter we will see Group by clause in more details. Linq Group by Mul...How to select multiple columns in Linq- C#.net VB.net code You want to select multiple columns using Linq query. Here are C#.net and VB.net examples. We will query Products table of North wind sample database and sel...Linq Union and intersect Example Linq Chapter 1 – Split string to list of strings. Linq Chapter 2 – Remove duplicates from list. Linq Chapter 3 – Linq Where Clause. Linq Chapt...

Linq Group By Multiple Columns ASp.net 2.0 step by step Membership Provider Linq Split String To List Linq Inner Join Linq Distinct List Linq Get Duplicate Count Of Words From String How to select multiple columns in Linq- C#.net VB.net code Linq Union and intersect Example C# ArrayList Search using Linq Extension OfType Method Linq to Sql Linq ToDictionary Extension

Author

My name is Satalaj, but people call me Sat. Here is my homepage: www.revenmerchantservices.com. I live in Pune, PN and work as a Software Engineer. I'm former MVP in ASP.net year 2010.

Disclaimer: Views or opinion expressed here are my personal research and it has nothing to do with my employer. You are free to use the code, ideas/hints in your projects. However, you should not copy and paste my original content to other web sites. Feel free to copy or extend the code.

If you want to fight with me, this website is not for you.

Satalaj More+

Satalaj