LINQ Grouping and Projecting

var repository = new EmployeeRepository();

Comprehensive Query Syntax

var queryByDepartment =
from e in repository.GetAll()
group e by e.DepartmentID
into eGroup
orderby eGroup.Key descending
where eGroup.Key < 3
select new
{
DepartmentID = eGroup.Key,
Count = eGroup.Count(),
Employees = eGroup
};

Extension Methods with Lambda Expressions

var queryByDepartment2 =

repository.GetAll()

.GroupBy(e=>e.DepartmentID)

.OrderByDescending(g=>g.Key)

.Where(g=>g.Key < 3)

.Select(g=>

new

{

DepartmentID = g.Key,

Count = g.Count(),

Employees = g

});

foreach(var group in queryByDepartment2)
{

Console.WriteLine("DID: {0}, Count: {1}",

group.DepartmentID,

group.Count);

foreach(var employee in group.Employees)

{

Console.WriteLine("\t{0}:{1}", employee.DepartmentID, employee.Name);

}

}