Highest Value in each Group using LINQ

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In this post, I will show you how to fetch the maximum value in each Group using LINQ

Let us consider you have the following class called Employees

C#

class Employees
{
    public int EmpId { get; set; }
    public int DeptId { get; set; }
    public int Salary { get; set; }
}

You want to find out the highest salary of an Employee in each Department. Here’s the LINQ query:

C#

List<Employees> emp = new List<Employees>();
// populate emp – demo by devcurry
// emp.Add(new Employees() { EmpId = 1, DeptId = 1, Salary = 20000 });

var highest = from e in emp
            group e by e.DeptId into dptgrp
              let topsal = dptgrp.Max(x => x.salary)
            select new
            {
                Dept = dptgrp.Key,
                TopSal = dptgrp.First(y => y.Salary == topsal).EmpId,
                MaximumSalary = topsal
            };

Here's a quick description. We first get the maximum salary in a department using

let topsal = dptgrp.Max(x => x.salary)

we then use the ‘topsal’ variable to compare it against the salary of an Employee in that department and then select the Empid

TopSal = dptgrp.First(y => y.Salary == topsal).EmpId

That's it and you will get the Employee with the highest salary in each department. To print the results, just use a loop and print the values - foreach(var a in highest){ }.

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About The Author

Suprotim Agarwal, Developer Technologies MVP (Microsoft Most Valuable Professional) is the founder and contributor for DevCurry, DotNetCurry and SQLServerCurry. He is the Chief Editor of a Developer Magazine called DNC Magazine. He has also authored two Books - 51 Recipes using jQuery with ASP.NET Controls. and The Absolutely Awesome jQuery CookBook.

Follow him on twitter @suprotimagarwal.