Linq query to return top two results when there is some conflict, is not working?

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I was trying simple thing, form a collection of employees I want to fetch top two maximum employees list. But remember there can be multiple employee with the same salary so I want all of them if they fall in max two salary range. below is my collection that I am using:

C#

List<Employee> Employees = new List<Employee>
            {
new Employee {EmployeeID = 1,EmployeeName  ="A", Department ="Dept1", Salary = 10000 },
new Employee {EmployeeID = 5,EmployeeName  ="A1", Department ="Dept2", Salary = 12000 },
new Employee {EmployeeID = 2,EmployeeName ="B", Department ="Dept1", Salary = 20000 },
new Employee {EmployeeID = 3,EmployeeName ="C",  Department ="Dept1", Salary = 20000 },
new Employee {EmployeeID = 6,EmployeeName ="B1", Department ="Dept2", Salary = 4500 },
new Employee {EmployeeID = 4,EmployeeName="D",  Department ="Dept1", Salary = 30000 },
            };

and Employee class is:

C#

public class Employee
    {
        public int EmployeeID { get; set; }
        public string EmployeeName { get; set; }
        public string Department { get; set; }
        public long Salary { get; set; }
    }

and below is my query:

C#

var result1 = from x in Employees
                    group x by x.Salary into g
                    from y in g.OrderBy(x=>x.Salary).Take(2)
                    select new { y.EmployeeID };

            foreach (var item in result1)
            {
                Console.WriteLine(item.EmployeeID);
            }

What I'm trying to do here is, first I am grouping all the employees based on their salaries. Then order these groups and take first two groups using TAKE extension method and then print all the employee those are in these two groups.

But I don't know why it's printing all the employees; it's not even ordering them. Can someone please share some thoughts and tell me what's wrong with this query?

What I have tried:

I've tried change the position of order by and group by still getting the same results.

Posted 27-Nov-16 7:51am

sunil kumar meena

Updated 27-Nov-16 8:17am

Wendelius

v3

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Wendelius · Accepted Answer · 2016-11-27T08:15:00

First of all, this is a very well formulated question with example data, nicely done!

One quite simple way could be to use two separate queries, one for fetching top salaries and the second one for employees, for example

C#

var topSal = from x in Employees
             group x by x.Salary into g
             orderby g.Key descending
             select new {
                TopSalary = g.Key
             };

var result1 = from x in Employees
              join s in topSal.Take(2) on x.Salary equals s.TopSalary
              select new { x.EmployeeID };

foreach (var item in result1) {
   Console.WriteLine(item.EmployeeID);
}

This could also be written using a single statement, for example

C#

var result2 = from x in Employees
              join s in Employees.Select(x1 => x1.Salary).Distinct().OrderByDescending(x2 => x2).Take(2) on x.Salary equals s
              select new { x.EmployeeID };

foreach (var item in result2) {
   Console.WriteLine(item.EmployeeID);
}