private static void PrintContextStudents(UniversityEntities context)
{
Console.WriteLine("=====================================");
foreach (var item in context.Students)
{
Console.WriteLine($"{item.Name} {item.Surname} =====>>>>> {item.Group.Name}");
}
Console.WriteLine("=====================================");
}
static void Main(string[] args)
{
UniversityEntities context = new UniversityEntities();
//Delete student (Name from keyboard)
Console.WriteLine("Delete student (Name from keyboard)");
//Alt+Enter - create function
PrintContextStudents(context);
Console.WriteLine();
try
{
Console.WriteLine("Enter Name student for DELETE: ");
string NameStudent = Console.ReadLine();
Student st = (Student)context.Students.FirstOrDefault(b => b.Name == NameStudent);
context.Students.Remove(st);
context.SaveChanges();
Console.WriteLine($"You deleted {NameStudent}");
}
catch
{
Console.WriteLine("Enter correct Name Student");
}
Console.WriteLine();
PrintContextStudents(context);
//Update Group in Student
Console.WriteLine("Update Group in Student (Name from keyboard)");
Console.WriteLine();
try
{
Console.WriteLine("Enter Name Student for UPDATE: ");
string NameStudent = Console.ReadLine();
Student st = (Student)context.Students.FirstOrDefault(b => b.Name == NameStudent);
Console.WriteLine("Enter New Name Group for UPDATE: ");
string NameGroupNew = Console.ReadLine();
st.Group.Name = NameGroupNew;
context.SaveChanges();
Console.WriteLine($"You update {st.Group.Name}");
}
catch
{
Console.WriteLine("Enter correct Name Student");
}
PrintContextStudents(context);
//Вивести всіх студентів певної групи
Console.WriteLine("Display all students in a group");
try
{
Console.WriteLine("Enter Name Group of find : ");
string NameGroup = Console.ReadLine();
Console.WriteLine("=====================================");
Console.WriteLine($"Students of group{NameGroup}: ");
foreach (var item in context.Students.Where(s => s.Group.Name == NameGroup))
{
Console.WriteLine($"{item.Name} {item.Surname} =====>>>>> {item.Group.Name}");
}
Console.WriteLine("=====================================");
}
catch
{
Console.WriteLine("Enter correct Name Group");
}
//Знайти кількість студентів двох груп
Console.WriteLine("Find the number of students in two groups");
try
{
Console.WriteLine("Enter First Group Name of find : ");
string NameGroupOne = Console.ReadLine();
Console.WriteLine("Enter Second Group Name of find : ");
string NameGroupTwo = Console.ReadLine();
int count = 0;
foreach (var item in context.Students.Where(s => s.Group.Name == NameGroupOne || s.Group.Name == NameGroupTwo))
{
count++;
}
if (count != 0)
{
Console.WriteLine($"Count Students of groups {NameGroupOne}+{NameGroupTwo} = {count}");
}
else
{
Console.WriteLine("Enter correct Name Group");
}
}
catch
{
Console.WriteLine("Enter correct Name Group");
}
//Знайти студента з максимальною оцінкою по предмету С++
Console.WriteLine("Find a student with the maximum grade in the subject C++");
var maxMark = context.Achievements.Where(x => x.Subject.Name == "C++" && x.Student != null).Select(x => x.Mark).Max();
Console.WriteLine("Mark => " + maxMark);
var studentsCS = context.Achievements.Where(x => x.Subject.Name == "C#" && x.Mark == maxMark && x.Student != null).Select(x => x.Student).ToList();
if (studentsCS != null)
{
foreach (var item in studentsCS)
{
Console.WriteLine($"{item.Name} {item.Surname} | {item.Group.Name}");
}
}
//Знайти всі предмети, які читає Андрій Трофімчук
Console.WriteLine("Find all subjects read by Andriy Trofimchuk");
var subjects = context.TeachersGroups.Where(x => x.Teacher.Name == "Andrii" && x.Teacher.Surname == "Trofimchuk").Select(x => x.Subject);
foreach (var item in subjects)
{
Console.WriteLine($"{item.Name} {item.Department.Name}");
}
//Знайти скільки студентів з іменем Оля
Console.WriteLine("Find how many students named Olya");
var nameOlia = context.Students.Count(x => x.Name == "Olia");
Console.WriteLine("Olia: " + nameOlia);
//Студенту з мінімальною оцінкою змінити прізвище
Console.WriteLine("A student with a minimum grade should change his / her last name");
//PrintContextStudents(context);
var minMark = context.Achievements.Where(x => x.Subject.Name == "C#" && x.Student != null).Select(x => x.Mark).Max();
Console.WriteLine("Min Mark => " + minMark);
var studentsMinCS = context.Achievements.Where(x => x.Subject.Name == "C#" && x.Mark == minMark && x.Student != null).Select(x => x.Student).ToList();
if (studentsMinCS != null)
{
foreach (var item in studentsMinCS)
{
Console.Write($"Enter new surname for {item.Name} {item.Surname}: ");
item.Surname = Console.ReadLine();
}
context.SaveChanges();
}
PrintContextStudents(context);
}