C#
Summary - LINQ query syntax
Combine from, where, select and group by to write an employee report.
Summary - LINQ query syntax
In this group you learned the from, where, select, orderby and group by ... into clauses. A query starts with from, ends with select or group; in between you filter, sort and transform.
Now you will combine them to build an employee report: first filter high-paid employees with where, then sort by department and salary with orderby and produce a tailored output.
Exercise Filter high-paid employees
Filter employees with salary 5500 or higher in the employees list using from e in employees where e.Salary >= 5500 select e. Iterate with foreach and print each name with Console.WriteLine(e.Name).
Show example solution
Write var wellPaid = from e in employees where e.Salary >= 5500 select e;. Then loop with foreach (var e in wellPaid) { Console.WriteLine(e.Name); }.
Example solution:
using System;
using System.Collections.Generic;
using System.Linq;
class Employee
{
public string Name { get; set; }
public string Department { get; set; }
public decimal Salary { get; set; }
}
class Program
{
static void Main()
{
var employees = new List<Employee>
{
new Employee { Name = "Ayşe", Department = "Sales", Salary = 5000 },
new Employee { Name = "Mehmet", Department = "IT", Salary = 7000 },
new Employee { Name = "Zeynep", Department = "Sales", Salary = 5500 },
new Employee { Name = "Alex", Department = "IT", Salary = 6500 }
};
var wellPaid = from e in employees
where e.Salary >= 5500
select e;
foreach (var e in wellPaid)
{
Console.WriteLine(e.Name);
}
}
}
Exercise Sort and print the employee report
Sort the high-paid employees with orderby e.Department, e.Salary descending (ascending by department, descending by salary). Iterate with foreach and for each employee write Console.WriteLine($"{e.Department} - {e.Name}: {e.Salary}").
Show example solution
{e.Salary}"); }.
Example solution:
using System;
using System.Collections.Generic;
using System.Linq;
class Employee
{
public string Name { get; set; }
public string Department { get; set; }
public decimal Salary { get; set; }
}
class Program
{
static void Main()
{
var employees = new List<Employee>
{
new Employee { Name = "Ayşe", Department = "Sales", Salary = 5000 },
new Employee { Name = "Mehmet", Department = "IT", Salary = 7000 },
new Employee { Name = "Zeynep", Department = "Sales", Salary = 5500 },
new Employee { Name = "Alex", Department = "IT", Salary = 6500 }
};
var report = from e in employees
where e.Salary >= 5500
orderby e.Department, e.Salary descending
select e;
foreach (var e in report)
{
Console.WriteLine($"{e.Department} - {e.Name}: {e.Salary}");
}
}
}
Test yourself
-
Which clause sorts in a query?
Show answer
orderby — Correct. Sorting is done with orderby.
-
Match each clause to its position
- from
- Start
- where
- Filter
- orderby
- Sort
- select
- Result
Next lesson: Expression<T>
