LINQ Cross Join

In LINQ, Cross join will produce the Cartesian product of the collections of items. There is no need for any condition to join the collection.

In LINQ Cross join, each element on the left side collection will be mapped to all the elements on the right side collection.

Syntax of LINQ Cross Join

Here is the syntax of using the LINQ Cross join to get the Cartesian product of the collection items.

var result = from e in objEmp1
from d in objDept1
select new
{
    EmployeeName = e.Name,
    DepartmentName = d.DepName
};

From the above syntax, each element in the "objEmp1" collection will be mapped to all the elements in the "objDept1" collection.

Example of LINQ Cross Join

Here is the example of using the LINQ Cross Join to get the Cartesian product of the collections of items.

using System;
using System. Collections;
using System.Collections.Generic;
using System. Linq;
using System. Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
    class Programme2
    {
        static void Main(string[] args)
        {
//Create the object of the Department List 'objDept1'  
            List<Department> objDept1 = new List<Department>(){
    //assign the value in the Department
            new Department{DepId=1,DepName="Software"},
            new Department{DepId=2,DepName="Finance"},
            new Department{DepId=3,DepName="Health"}
};
    //Create the object of Employee List 'objEmp1'
            List<Employee> objEmp1 = new List<Employee>()

{
//Insert the value in the Employee list
new Employee { EmpId=1,Name = "Vaishali Tyagi", DeptId=1 },

new Employee { EmpId=2,Name = "Arpita Rai", DeptId=1 },

new Employee { EmpId=3,Name = "Vinay Tyagi", DeptId=2 },

new Employee { EmpId=4,Name = "Sateesh", DeptId =2},

new Employee { EmpId=5,Name = "Madhav"}

};
    /*apply the linq queries to fetch the value from the Employee 
    and Department list and store the value in variable 'result'*/
            var result = from e in objEmp1

                         from d in objDept1
    //Select will fetch the name of the employee and name of the department
                         select new

                         {

                             EmployeeName = e.Name,

                             DepartmentName = d.DepName

                         };
    //foreach loop will print the value of the result with the help of 'WriteLine' funtion
            foreach (var item in result)

            {

                Console.WriteLine(item.EmployeeName + "\t | " + item.DepartmentName);

            }

            Console.ReadLine();

        }

    }
    //Here we create the class named Department and Employee and assignt the variable 
    class Department

    {

        public int DepId { get; set; }

        public string DepName { get; set; }

    }

    class Employee

    {

        public int EmpId { get; set; }

        public string Name { get; set; }

        public int DeptId { get; set; }

    }

}

In the above example, we didn't mention any condition to join the collections.

Output: