What is LINQ sorting operator?

Ethan Karla 427 24 Sep 2021

How to use OrderBy, OrderByDescending, ThenBy, ThenByDescending, and Reverse on sorting technique in LINQ.

Ethan Karla

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An enthusiastic, adaptive, and fast-learning person with a broad and acute interest in the discovery of new innovative drugs, I particularly enjoy collaborating with scientists from different disciplines to develop new skills and solve new challenges.

1 Answers

Ravi Vishwakarma 27 Sep 2021

In LINQ, the sorting operators are used to sort data in ascending or descending order based on one or more attributes in Collection or SQL Server database.

There are following are the different types of sorting operators.

Operator in LINQ	methods in LINQ	details of operator
orderby	orderby()	sort data by default in ascending order
orderby ... descending	OrderByDescending()	sort data by default in descending order
orderby ... , ...	ThenBy()	this sort is used for secondary sorting by default ascending order
orderby ... , ... descending	ThenByDescending()	this sort is used for secondary sorting by default descending order
N/A	Reverse()	this sort the data in reverse order

orderby and orderby ... descending

Syntax

datatype variable-name = from object in collection
                         where condition
                         orderby condition
                         select student ;

datatype variable-name = from object in collection

                         where condition

                         orderby condition descending
                         select student ;

Example

using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

 public static void Main()

 {

  List<Student> students = new List<Student>()

  {

  new Student() { StudentId = 1, Name = 'Asu', Marks = 500 },

  new Student() { StudentId = 2, Name = 'Shyam', Marks = 300 },

  new Student() { StudentId = 3, Name = 'Shriyam', Marks = 400 },

  new Student() { StudentId = 4, Name = 'Sunny', Marks = 550 },

  new Student() { StudentId = 5, Name = 'Ram', Marks = 600 },

  new Student() { StudentId = 6, Name = 'Krishna', Marks = 700 },

  new Student() { StudentId = 7, Name = 'Anupam', Marks = 550 }

  };

  // select projection using first sysntax

  var result1= from student in students 

      where student.Marks > 300 && student.Marks < 700

      orderby student.Marks

      select student ;

  Console.WriteLine('Accending order\n');

  Console.WriteLine('{0,-10} {1,10} {2,5}','Name', 'ID', 'Marks');

  result1.ToList().ForEach(item => Console.WriteLine('{0,-10} {1,10} {2,5}', item.Name, item.StudentId, item.Marks) );

  var result2= from student in students 

      where student.Marks > 300 && student.Marks < 700

      orderby student.Marks descending

      select student ;

  Console.WriteLine('\nDescending order\n');

  Console.WriteLine('{0,-10} {1,10} {2,5}','Name', 'ID', 'Marks');

  result2.ToList().ForEach(item => Console.WriteLine('{0,-10} {1,10} {2,5}', item.Name, item.StudentId, item.Marks) );

  var result3 = students.Where( student => student.StudentId < 5).OrderBy(stu => stu.Marks);

  Console.WriteLine('\nAccending order using where method Syntax :\n');

  Console.WriteLine('{0,-10} {1,10} {2,5}','Name', 'ID', 'Marks');

  result3.ToList().ForEach(item => Console.WriteLine('{0,-10} {1,10} {2,5}', item.Name, item.StudentId, item.Marks) );

  Console.ReadLine();

 }

}

class Student

{

public int StudentId { get; set; }

public string Name { get; set; }

public int Marks { get; set; }

}

Output:

Accending order

Name               ID Marks

Shriyam             3   400

Asu                 1   500

Sunny               4   550

Anupam              7   550

Ram                 5   600

Descending order

Name               ID Marks

Ram                 5   600

Sunny               4   550

Anupam              7   550

Asu                 1   500

Shriyam             3   400

Accending order using where method Syntax :

Name               ID Marks

Shyam               2   300

Shriyam             3   400

Asu                 1   500

Sunny               4   550

thenby and theneby... descending

Syntax

datatype variable-name = from object in collection

                         where condition
                         orderby condition, condition
                         select student ;

datatype variable-name = from object in collection

                         where condition

                         orderby condition, condition descending

                         select student ;

Example

using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

 public static void Main()

 {

  List<Student> students = new List<Student>()

  {

  new Student() { StudentId = 1, Name = 'Asu', Marks = 500 },

  new Student() { StudentId = 2, Name = 'Shyam', Marks = 300 },

  new Student() { StudentId = 3, Name = 'Shriyam', Marks = 400 },

  new Student() { StudentId = 4, Name = 'Sunny', Marks = 550 },

  new Student() { StudentId = 5, Name = 'Ram', Marks = 600 },

  new Student() { StudentId = 6, Name = 'Krishna', Marks = 700 },

  new Student() { StudentId = 7, Name = 'Anupam', Marks = 550 }

  };

  // select projection using first sysntax

  var result1= from student in students 

      where student.Marks > 300 && student.Marks < 700

      orderby student.Marks, student.StudentId

      select student ;

  Console.WriteLine('Accending order\n');

  Console.WriteLine('{0,-10} {1,10} {2,5}','Name', 'ID', 'Marks');

  result1.ToList().ForEach(item => Console.WriteLine('{0,-10} {1,10} {2,5}', item.Name, item.StudentId, item.Marks) );

  var result2= from student in students 

      where student.Marks > 300 && student.Marks < 700

      orderby student.Marks,student.StudentId descending

      select student ;

  Console.WriteLine('\nDescending order\n');

  Console.WriteLine('{0,-10} {1,10} {2,5}','Name', 'ID', 'Marks');

  result2.ToList().ForEach(item => Console.WriteLine('{0,-10} {1,10} {2,5}', item.Name, item.StudentId, item.Marks) );

  var result3 = students.Where( student => student.StudentId < 5).OrderBy(stu => stu.Marks).ThenBy( stu => stu.StudentId);

  Console.WriteLine('\nAccending order using where method Syntax :\n');

  Console.WriteLine('{0,-10} {1,10} {2,5}','Name', 'ID', 'Marks');

  result3.ToList().ForEach(item => Console.WriteLine('{0,-10} {1,10} {2,5}', item.Name, item.StudentId, item.Marks) );

  Console.ReadLine();

 }

}

class Student

{

public int StudentId { get; set; }

public string Name { get; set; }

public int Marks { get; set; }

}

Output

Accending order

Name               ID Marks

Shriyam             3   400

Asu                 1   500

Sunny               4   550

Anupam              7   550

Ram                 5   600

Descending order

Name               ID Marks

Shriyam             3   400

Asu                 1   500

Anupam              7   550

Sunny               4   550

Ram                 5   600

Accending order using where method Syntax :

Name               ID Marks

Shyam               2   300

Shriyam             3   400

Asu                 1   500

Sunny               4   550

Reverse

using System;

using System.Collections.Generic;

using System.Linq;

public class Program

{

 public static void Main()

 {

  List<Student> students = new List<Student>()

  {

  new Student() { StudentId = 1, Name = 'Asu', Marks = 500 },

  new Student() { StudentId = 2, Name = 'Shyam', Marks = 300 },

  new Student() { StudentId = 3, Name = 'Shriyam', Marks = 400 },

  new Student() { StudentId = 4, Name = 'Sunny', Marks = 550 },

  new Student() { StudentId = 5, Name = 'Ram', Marks = 600 },

  new Student() { StudentId = 6, Name = 'Krishna', Marks = 700 },

  new Student() { StudentId = 7, Name = 'Anupam', Marks = 550 }

  };

  var result3 = students.Where( student => student.StudentId < 5).Reverse();

  Console.WriteLine('\nReverse order using where method Syntax :\n');

  Console.WriteLine('{0,-10} {1,10} {2,5}','Name', 'ID', 'Marks');

  result3.ToList().ForEach(item => Console.WriteLine('{0,-10} {1,10} {2,5}', item.Name, item.StudentId, item.Marks) );

  Console.ReadLine();

 }

}

class Student

{

public int StudentId { get; set; }

public string Name { get; set; }

public int Marks { get; set; }

}

Output

Reverse order using where method Syntax :

Name               ID Marks

Sunny               4   550

Shriyam             3   400

Shyam               2   300

Asu                 1   500

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What is LINQ sorting operator?

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