LINQ Query Syntax

There are two basic ways to write a LINQ query to IEnumerable collection or IQueryable data sources.

1. Query Syntax or Query Expression Syntax

2. Method Syntax or Method Extension Syntax or Fluent

Query Syntax

Query syntax is similar to SQL (Structured Query Language) for the database. It is defined within the C# or VB code.LINQ Query Syntax:

from <range variable> in <IEnumerable<T> or IQueryable<T> Collection>

<Standard Query Operators> <lambda expression>

<select or groupBy operator> <result formation>

The LINQ query syntax starts with from keyword and ends with select keyword. The following is a sample LINQ query that returns a collection of strings which contains a word "Tutorials".

// string collection
IList<string> stringList = new List<string>() { 
    "C# Tutorials",
    "VB.NET Tutorials",
    "Learn C++",
    "MVC Tutorials" ,
    "Java" 
};

// LINQ Query Syntax
var result = from s in stringList
            where s.Contains("Tutorials") 
            select s;

The following figure shows the structure of LINQ query syntax.LINQ Query Syntax

Query syntax starts with a From clause followed by a Range variable. The From clause is structured like "From rangeVariableName in IEnumerablecollection". In English, this means, from each object in the collection. It is similar to a foreach loop: foreach(Student s in studentList).