public static void StudentByGollege()
{
var studentGroups = Student.GetAllStudents().GroupBy(x => x.College);
//var studentGroups = from students in Student.GetAllStudents()
// group students by students.College into sGroup
// orderby sGroup.Key
// select new { Key=sGroup.Key, Students=sGroup};
foreach (var item in studentGroups)
{
Console.WriteLine(item.Key + " - " + item.Count(x => x.Gender == "Male") + " " + item.Max(x => x.Age));
foreach (var student in item)
{
Console.WriteLine($"{student.FirstName} {student.LastName} {student.Gender}");
}
}
}
public static void Deferred()
{
var allStudents = Student.GetAllStudents().ToList();
var femaleStudent = from student in allStudents
where student.Gender == "Female"
select student;
//var femaleStudent = (from student in allStudents
// where student.Gender == "Female"
// select student).ToList();
allStudents.Add(new Student {
FirstName = "Anisa", LastName = "Sadieva", Gender = "Female"
});
foreach (var item in femaleStudent)
{
Console.WriteLine(item.FirstName + " " + item.LastName);
}
}
static void Main(string[] args)
{
IEnumerable <string> names = Student.GetAllStudents().Select(s => s.FirstName + " " + s.LastName);
foreach (var item in names)
{
Console.WriteLine(item);
}
Console.WriteLine("########################################");
IEnumerable <string> myCourses = Student.GetAllStudents().SelectMany(s => s.Courses).Distinct();
foreach (var item in myCourses)
{
Console.WriteLine(item);
}
Console.WriteLine("########################################");
IEnumerable <string> myCoursesSQL = (from student in Student.GetAllStudents()
from course in student.Courses
select course).Distinct();
foreach (var item in myCourses)
{
Console.WriteLine(item);
}
Console.WriteLine("########################################");
var students = Student.GetAllStudents().SelectMany(s => s.Courses, (s, course) => new { Name = s.FirstName + " " + s.LastName, Course = course });
foreach (var item in students)
{
Console.WriteLine(item.Name + '\t' + item.Course);
}
Console.WriteLine("########################################");
var studentsSQL = from student in Student.GetAllStudents()
from course in student.Courses
select new { Name = student.FirstName + " " + student.LastName, Course = course };
foreach (var item in studentsSQL)
{
Console.WriteLine(item.Name + '\t' + item.Course);
}
Console.WriteLine("########################################");
var studentsOrderBy = Student.GetAllStudents().OrderBy(s => s.LastName).ThenBy(s => s.FirstName);// or OrderByDescending() / ThenByDescending()
//var SQLversion = from student in Student.GetAllStudents()
// orderby student.LastName, student.FirsName descending // or ascending
// select student;
foreach (var item in studentsOrderBy)
{
Console.WriteLine(item.LastName + '\t' + item.FirstName);
}
Console.WriteLine("########################################");
var studentsReverse = (from student in Student.GetAllStudents()
select student).Reverse();
foreach (var item in studentsReverse)
{
Console.WriteLine(item.LastName + '\t' + item.FirstName);
}
Console.WriteLine("########################################");
DeferredExecution.Deferred();
Console.WriteLine("########################################");
GroupBy.StudentByGollege();
Console.ReadKey();
}