static void Main()
{
StudentsDirectory database1 = new StudentsDirectory();
SpecialtiesDirectory database2 = new SpecialtiesDirectory();
// LINQ query
var joinedData =
from student in database1.Students
orderby student.FirstName ascending, student.LastName ascending
join speciality in database2.StudentSpecialties on student.FacultyNumber equals speciality.FacultyNumber
select new { student.FirstName, student.LastName, student.FacultyNumber, speciality.Speciality };
// lambda expression
var joinedDataLinqExtMtd =
database1.Students.OrderBy(st => st.FirstName)
.ThenBy(st => st.LastName)
.Join(database2.StudentSpecialties, st => st.FacultyNumber, sp => sp.FacultyNumber,
(student, speciality) =>
new { student.FirstName, student.LastName, student.FacultyNumber, speciality.Speciality });
// printing
Console.WriteLine("{0, -18} {1, -8} {2, -12}", "Name", "FacNum", "Specialty");
foreach (var item in joinedData)
{
Console.WriteLine("{0, -18} {1, -8} {2, -12}", item.FirstName + " " + item.LastName, item.FacultyNumber, item.Speciality);
}
}
public static List <StudentWithGroup> CreateGroupsDirectory()
{
var studentsWithGroups = new List <StudentWithGroup>();
// using the intitial students databae, to create new studets with groups database
StudentsDirectory database = new StudentsDirectory();
foreach (var student in database.Students)
{
if (student.GroupNumber == 1)
{
studentsWithGroups.Add(new StudentWithGroup(student, "C#"));
}
else if (student.GroupNumber == 2)
{
studentsWithGroups.Add(new StudentWithGroup(student, "PHP"));
}
else if (student.GroupNumber == 3)
{
studentsWithGroups.Add(new StudentWithGroup(student, "JS"));
}
else if (student.GroupNumber == 4)
{
studentsWithGroups.Add(new StudentWithGroup(student, "Java"));
}
else
{
studentsWithGroups.Add(new StudentWithGroup(student, "No group chosen"));
}
}
return(studentsWithGroups);
}
static void Main()
{
// creating an instance of the StudentsDirectory class, so that we can use its IList<Student>
StudentsDirectory database = new StudentsDirectory();
// running LINQ query
var studentsByPhoneQuery = database.Students.StudentsByPhoneQuery();
// printing - by invoking the PrintStudentsInfo() method from the StudentsByFirstAndLastName project
StudentsByFirstAndLastName.PrintStudentsInfo(studentsByPhoneQuery);
}
static void Main()
{
// creating an instance of the StudentsDirectory class, so that we can use its IList<Student>
StudentsDirectory database = new StudentsDirectory();
// running LINQ query
var studentsByNames = database.Students.StudentsByNames();
// printing
PrintStudentsInfo(studentsByNames);
}
static void Main()
{
// creating an instance of the StudentsDirectory class, so that we can use its IList<Student>
StudentsDirectory database = new StudentsDirectory();
// running LINQ query
var studentsByGroupQuery =
from student in database.Students
orderby student.FirstName
group student by student.GroupNumber
into studentGroup
where studentGroup.Key == 2
select studentGroup;
// printing
PrintStudentInfoByGroup(studentsByGroupQuery);
}
static void Main()
{
// creating an instance of the StudentsDirectory class, so that we can use its IList<Student>
StudentsDirectory database = new StudentsDirectory();
// running LINQ query
var excellentStudents =
from student in database.Students
where student.Marks.Contains(6)
select new { Fullname = string.Join(" ", student.FirstName, student.LastName), Marks = string.Join(", ", student.Marks) };
// printing
foreach (var student in excellentStudents)
{
Console.WriteLine("Name: {0}, Grades: {{{1}}}", student.Fullname, student.Marks);
}
}
static void Main()
{
// creating an instance of the StudentsDirectory class, so that we can use its IList<Student>
StudentsDirectory database = new StudentsDirectory();
// using lambda expressions
var sortedStudents =
database.Students.OrderByDescending(student => student.FirstName).ThenBy(student => student.LastName);
// running LINQ query
var studentsSortQuery = database.Students.StudentsSortQuery();
// printing - by invoking the PrintStudentsInfo() method from the StudentsByFirstAndLastName project
StudentsByFirstAndLastName.PrintStudentsInfo(sortedStudents);
Console.WriteLine();
StudentsByFirstAndLastName.PrintStudentsInfo(studentsSortQuery);
}
static void Main()
{
// creating an instance of the StudentsDirectory class, so that we can use its IList<Student>
StudentsDirectory database = new StudentsDirectory();
// running LINQ query
var studentsByAgeQuery =
from student in database.Students
where student.Age >= 18 && student.Age <= 24
select new { student.FirstName, student.LastName, student.Age }; // limiting the query to names and age
// printing
foreach (var student in studentsByAgeQuery)
{
Console.WriteLine("Name: {0} {1}, Age: {2}",
student.FirstName, student.LastName, student.Age);
}
}
