In this tutorial, we will learn about sorting operators - OrderBy & OrderByDescending in LINQ
In LINQ, sorting operators are used to sort the data from the collection in a specific order such as in ascending or descending order. In this tutorial, we will learn about the sorting operators - OrderBy & OrderByDescending.
In LINQ, OrderBy is used to sort the data in the collection based on a specific field in a specific order i.e. either in ascending order or in descending order.
By default, it sorts the data in the collection in an ascending order.
The ascending keyword is optional but if you want to sort the collection in descending order, use the descending keyword.
In this example, we used the OrderBy operator and sorted the collection in ascending and descending order. By default, OrderBy sorts the collection in ascending order, we use the descending keyword for sorting the collection in descending order.
using System;
using System.Linq;
using System.Collections.Generic;
public class Program
{
public static void Main()
{
// Employee collection
IList<Employee> employeelist = new List<Employee>() {
new Employee() { EmpID = 1, EmpName = "John", City = "New York", Salary = 130000} ,
new Employee() { EmpID = 2, EmpName = "Moin", City = "New Orleans", Salary = 210000 } ,
new Employee() { EmpID = 3, EmpName = "Bill", City = "Seattle", Salary = 180000 } ,
new Employee() { EmpID = 4, EmpName = "Ram" , City = "Delhi", Salary = 200000} ,
new Employee() { EmpID = 5, EmpName = "Ron" , City = "San Jose", Salary = 150000 }
};
// LINQ Query Syntax to sort an Employe
// in an Ascending and Descending Order based on EmpName
Console.WriteLine("--Employee Data in Ascending Order--");
var orderByResult = from s in employeelist
orderby s.EmpName
select s;
foreach (var emp in orderByResult)
{
Console.WriteLine($"EmpId = {emp.EmpID}; EmpName = {emp.EmpName}; City = {emp.City}");
}
Console.WriteLine();
Console.WriteLine("--Employee Data in Descending Order--");
var orderByDescendingResult = from s in employeelist
orderby s.EmpName descending
select s;
foreach (var emp in orderByDescendingResult)
{
Console.WriteLine($"EmpId = {emp.EmpID}; EmpName = {emp.EmpName}; City = {emp.City}");
}
Console.ReadKey();
}
}
public class Employee
{
public int EmpID { get; set; }
public string EmpName { get; set; }
public string City { get; set; }
public int Salary { get; set; }
}
--Employee Data in Ascending Order--
EmpId = 3; EmpName = Bill; City = Seattle
EmpId = 1; EmpName = John; City = New York
EmpId = 2; EmpName = Moin; City = New Orleans
EmpId = 4; EmpName = Ram; City = Delhi
EmpId = 5; EmpName = Ron; City = San Jose
--Employee Data in Descending Order--
EmpId = 5; EmpName = Ron; City = San Jose
EmpId = 4; EmpName = Ram; City = Delhi
EmpId = 2; EmpName = Moin; City = New Orleans
EmpId = 1; EmpName = John; City = New York
EmpId = 3; EmpName = Bill; City = Seattle
When you use OrderBy with the method syntax, then this OrderBy extension method has two overloads:
The first overload method of OrderBy accepts the Func delegate type parameter, so you just need to pass the lambda expression for the field-based sorting on the collection.
public static IOrderedEnumerable<TSource> OrderBy<TSource, TKey>(this IEnumerable<TSource> source,
Func<TSource, TKey> keySelector);
The second overload of OrderBy accepts the object of IComparer along with the Func delegate type parameter to use custom comparison for sorting collection.
public static IOrderedEnumerable<TSource> OrderBy<TSource, TKey>(this IEnumerable<TSource> source,
Func<TSource, TKey> keySelector,
IComparer<TKey> comparer);
Here is the example of OrderBy using Method Syntax:
using System;
using System.Collections.Generic;
using System.Linq;
namespace LinqPrograms
{
internal class Program
{
public static void Main(string[] args)
{
// Employee collection
IList<Employee> employeelist = new List<Employee>() {
new Employee() { EmpID = 1, EmpName = "John", City = "New York", Salary = 130000} ,
new Employee() { EmpID = 2, EmpName = "Moin", City = "New Orleans", Salary = 210000 } ,
new Employee() { EmpID = 3, EmpName = "Bill", City = "Seattle", Salary = 180000 } ,
new Employee() { EmpID = 4, EmpName = "Ram" , City = "Delhi", Salary = 200000} ,
new Employee() { EmpID = 5, EmpName = "Ron" , City = "San Jose", Salary = 150000 }
};
// LINQ Method Syntax to sort an Employe
// in an Ascending Order based on EmpName
Console.WriteLine("--Employee Data in Ascending Order--");
var orderByResult = employeelist.OrderBy(e => e.EmpName);
foreach (var emp in orderByResult)
{
Console.WriteLine($"EmpId = {emp.EmpID}; EmpName = {emp.EmpName}; City = {emp.City}");
}
Console.ReadKey();
}
}
public class Employee
{
public int EmpID { get; set; }
public string EmpName { get; set; }
public string City { get; set; }
public int Salary { get; set; }
}
}
--Employee Data in Ascending Order--
EmpId = 3; EmpName = Bill; City = Seattle
EmpId = 1; EmpName = John; City = New York
EmpId = 2; EmpName = Moin; City = New Orleans
EmpId = 4; EmpName = Ram; City = Delhi
EmpId = 5; EmpName = Ron; City = San Jose
Note: Method syntax does not support the descending keyword to sort the collection in descending order. For sorting the collection in descending order with method syntax, use the OrderByDecending() method.
In LINQ, OrderByDescending() is used to sort the data in the collection based on specific fields in descending order. This method supports only method syntax. Here is an example to sort the collection using OrderByDescending() method:
using System;
using System.Collections.Generic;
using System.Linq;
namespace LinqPrograms
{
internal class Program
{
public static void Main(string[] args)
{
// Employee collection
IList<Employee> employeelist = new List<Employee>() {
new Employee() { EmpID = 1, EmpName = "John", City = "New York", Salary = 130000} ,
new Employee() { EmpID = 2, EmpName = "Moin", City = "New Orleans", Salary = 210000 } ,
new Employee() { EmpID = 3, EmpName = "Bill", City = "Seattle", Salary = 180000 } ,
new Employee() { EmpID = 4, EmpName = "Ram" , City = "Delhi", Salary = 200000} ,
new Employee() { EmpID = 5, EmpName = "Ron" , City = "San Jose", Salary = 150000 }
};
// LINQ Method Syntax to sort an Employe
// in a Descending Order based on EmpName
Console.WriteLine("--Employee Data in Descending Order--");
var orderByResult = employeelist.OrderByDescending(e => e.EmpName);
foreach (var emp in orderByResult)
{
Console.WriteLine($"EmpId = {emp.EmpID}; EmpName = {emp.EmpName}; City = {emp.City}");
}
Console.ReadKey();
}
}
public class Employee
{
public int EmpID { get; set; }
public string EmpName { get; set; }
public string City { get; set; }
public int Salary { get; set; }
}
}
--Employee Data in Descending Order--
EmpId = 5; EmpName = Ron; City = San Jose
EmpId = 4; EmpName = Ram; City = Delhi
EmpId = 2; EmpName = Moin; City = New Orleans
EmpId = 1; EmpName = John; City = New York
EmpId = 3; EmpName = Bill; City = Seattle
In LINQ, you can sort the collection on multiple fields which are separated by a comma. Here is an example to sort the collection using multiple fields:
using System;
using System.Collections.Generic;
using System.Linq;
namespace LinqPrograms
{
internal class Program
{
public static void Main(string[] args)
{
// Employee collection
IList<Employee> employeelist = new List<Employee>() {
new Employee() { EmpID = 1, EmpName = "John", City = "New York", Salary = 130000} ,
new Employee() { EmpID = 2, EmpName = "Moin", City = "New Orleans", Salary = 210000 } ,
new Employee() { EmpID = 3, EmpName = "Bill", City = "Seattle", Salary = 180000 } ,
new Employee() { EmpID = 4, EmpName = "Ram" , City = "Delhi", Salary = 200000} ,
new Employee() { EmpID = 5, EmpName = "Ron" , City = "San Jose", Salary = 150000 },
new Employee() { EmpID = 6, EmpName = "Bill" , City = "Chicago", Salary = 250000 }
};
// LINQ Query Syntax to sort an Employe
// in a ascending Order based on multiple
// fields like EmpName, Salary
Console.WriteLine("--Employee Data Sorted on Multiple Field in Ascending Order--");
var orderByResult = from s in employeelist
orderby s.EmpName, s.Salary
select s;
foreach (var emp in orderByResult)
{
Console.WriteLine($"EmpId = {emp.EmpID}; EmpName = {emp.EmpName}; City = {emp.City}; Salary = {emp.Salary}");
}
Console.ReadKey();
}
}
public class Employee
{
public int EmpID { get; set; }
public string EmpName { get; set; }
public string City { get; set; }
public int Salary { get; set; }
}
}
--Employee Data Sorted on Multiple Field in Ascending Order--
EmpId = 3; EmpName = Bill; City = Seattle; Salary = 180000
EmpId = 6; EmpName = Bill; City = Chicago; Salary = 250000
EmpId = 1; EmpName = John; City = New York; Salary = 130000
EmpId = 2; EmpName = Moin; City = New Orleans; Salary = 210000
EmpId = 4; EmpName = Ram; City = Delhi; Salary = 200000
EmpId = 5; EmpName = Ron; City = San Jose; Salary = 150000
ThenBy() & ThenByDescending() methods for secondary sorting.Learn Sorting Operator - ThenBy & ThenByDescending in the next tutorial.