static void Main(string[] args)
{
//display name
using (var db = new EfExampleEntities())
{
var students = db.Students.Select(x => x.Name);
foreach (var student in students)
{
Console.WriteLine(student);
}
}
Console.WriteLine();
//display course
using (var db = new EfExampleEntities())
{
var students = db.Students;
foreach (var student in students)
{
Console.WriteLine(student.Name + ":");
foreach (var course in student.Courses)
{
Console.WriteLine(course.Name);
}
}
}
//display teacher for student
using (var db = new EfExampleEntities())
{
var students = db.Students;
foreach (var student in students)
{
Console.WriteLine(student.Name + ":");
foreach (var course in student.Courses)
{
Console.WriteLine(course.Teacher.Staff.Name);
}
}
}
//display staff thats not teacher
using (var db = new EfExampleEntities())
{
var staff = db.Staff.Where(s => s.Teacher == null);
foreach (var staffmember in staff)
{
Console.WriteLine(staffmember.Name);
}
}
//names of students in hist101
using (var db = new EfExampleEntities())
{
foreach (var student in db.Students.Where(s => s.Courses.Any(c => c.Name == "math101")))
{
Console.WriteLine(student.Name);
}
}
//mikes (8) ass got fired and barbra gets his classes barbs id = 7
using (var db = new EfExampleEntities())
{
var barbara = db.Teachers.Find(7);
var courses = db.Teachers.Find(8).Courses.ToList();
foreach (var course in courses)
{
course.Teacher = barbara;
db.Entry(course).State = System.Data.Entity.EntityState.Modified;
}
db.SaveChanges();
}
Console.ReadKey(true);
}
static void Main(string[] args)
{
void Print <T>(IEnumerable <T> things)
{
foreach (T thing in things)
{
Console.Write(thing + " ");
}
Console.WriteLine();
}
EfExampleEntities db = new EfExampleEntities();
using (db)
{
//Print the names of all the students.
Print(db.Students.Select(x => x.Name));
//Print the names of all the courses.
Print(db.Courses.Select(x => x.Name));
//Print the number of courses that have no students enrolled.
Console.WriteLine(db.Courses.Count(x => x.Students.Count() == 0));
//Print the names of all the teachers.
Print(db.Staff.Where(x => x.Teacher != null).Select(x => x.Name));
//Remove "Mike Teacher" from the database.
var mike = db.Teachers.First(x => x.Staff.Name == "Mike Teacher");
mike.Courses.Select((x) => x.Teacher = null);
db.Entry(mike.Staff).State = System.Data.Entity.EntityState.Deleted;
db.Entry(mike).State = System.Data.Entity.EntityState.Deleted;
db.SaveChanges();
//Print the names of all the teachers again.
Print(db.Staff.Where(x => x.Teacher != null).Select(x => x.Name));
//Give every teacher a 1.5 % raise.
var res = db.Staff.Where(x => x.Teacher != null);
var cours = db.Courses;
foreach (Staff staff in res)
{
staff.Salary = staff.Salary + (int)(0.015 * staff.Salary);
db.Entry(staff).State = System.Data.Entity.EntityState.Modified;
}
db.SaveChanges();
Print(db.Staff.Where(x => x.Teacher != null).Select(x => x.Salary));
//Give every staff member who is NOT a teacher a 30 % raise.
var res2 = db.Staff.Where(x => x.Teacher == null);
foreach (Staff staff in res2)
{
staff.Salary = staff.Salary + (int)(0.3 * staff.Salary);
db.Entry(staff).State = System.Data.Entity.EntityState.Modified;
}
db.SaveChanges();
Print(db.Staff.Where(x => x.Teacher == null).Select(x => x.Salary));
//Take John Student out of the HIST101 class.
var john = db.Students.Single(x => x.Name == "John Student");
var course = db.Courses.Single(x => x.Name == "Hist101");
course.Students.Remove(john);
john.Courses.Remove(course);
db.Entry(john).State = System.Data.Entity.EntityState.Modified;
db.Entry(course).State = System.Data.Entity.EntityState.Modified;
db.SaveChanges();
Print(john.Courses.Select(x => x.Name));
//EXTRA(OPTIONAL) : Make a new console application and a new database.Using Entity Framework Code First, recreate the same tables and foreign key constraints that EfExample has.
db.Dispose();
}
Console.ReadKey(true);
}
