To print the results, I am using a utility class called ObjectDumper which can be obtained from here. The structure of the classes representing a Parent-Child relationship is shown below. Each Department has many Employees, but one Employee belongs to only one Department
C#
public class Department
{
public int DeptID { get; set; }
public string DeptName { get; set; }
public List<Employee> employee { get; set; }
}
public class Employee
{
public int EmpID { get; set; }
public int DeptID { get; set; }
public string Name { get; set; }
public int AgeInYrs { get; set; }
}
Sample Data
List<Department> lists = new List<Department>()
{
new Department()
{
DeptID = 1, DeptName = "Marketing", employee = new List<Employee>
{
new Employee() { EmpID = 9, DeptID = 1, Name = "Jack Nolas", AgeInYrs = 28 },
new Employee() { EmpID = 5, DeptID = 1, Name = "Mark Pine" , AgeInYrs = 42 },
new Employee() { EmpID = 3, DeptID = 1, Name = "Sandra Simte" , AgeInYrs = 38 },
new Employee() { EmpID = 8, DeptID = 1, Name = "Larry Lo" , AgeInYrs = 31 }
}
},
new Department()
{
DeptID = 2, DeptName = "Sales", employee = new List<Employee>
{
new Employee() { EmpID = 1, DeptID = 2, Name = "Sudhir Panj" , AgeInYrs = 28 },
new Employee() { EmpID = 7, DeptID = 2, Name = "Kathy Karlo" , AgeInYrs = 43 },
new Employee() { EmpID = 4, DeptID = 2, Name = "Dinesh Kumar" , AgeInYrs = 34 }
}
},
new Department()
{
DeptID = 3, DeptName = "HR", employee = new List<Employee>
{
new Employee() { EmpID = 2, DeptID = 3, Name = "Kaff Joe" , AgeInYrs = 25 },
new Employee() { EmpID = 6, DeptID = 3, Name = "Su Lie" , AgeInYrs = 52 },
new Employee() { EmpID = 10, DeptID = 3, Name = "Malcolm Birt" , AgeInYrs = 41 }
}
}
};
Here are some common Operations on a Hierarchical Parent-Child List. Please use this Converter Tool to convert the code to VB.NET
1. List Employees in Each Department
var empInDept = lists
.Select(emp => new
{
Department = emp.DeptName,
Employee = emp.employee.Select(e => e.Name)
});
ObjectDumper.Write(empInDept, 1);
2. Print the Average Age of Employees in each Department
var avgAgePerDept = lists
.Select(emp => new
{
Department = emp.DeptName,
AverageAge = emp.employee.Average(avg => (double)avg.AgeInYrs)
});
ObjectDumper.Write(avgAgePerDept, 1);
3. List only those Employees in each Department with Age > 30
var empGt30 = lists
.Select(emp => new
{
Department = emp.DeptName,
Emp = emp.employee.Where(em => em.AgeInYrs > 30)
.Select(e => new
{
EmployeeName = e.Name,
Age = e.AgeInYrs
})
});
ObjectDumper.Write(empGt30, 1);
4. Count the number of Employees in each Department
var cntEmpPerDept = lists
.Select(emp => new
{
Department = emp.DeptName,
NoOfEmployees = emp.employee.Count()
});
ObjectDumper.Write(cntEmpPerDept, 1);
5. Sort and List Employees in each Department
var ordered = lists
.Select(emp => new
{
Department = emp.DeptName,
Employee = emp.employee.OrderBy(e => e.Name)
.Select(c => new
{
Name = c.Name
})
});
ObjectDumper.Write(ordered, 1);
