public static void PrintDatabase()
{
using (var db = new ManyToManyDatabase())
{
Console.WriteLine("Lessons:");
foreach (var lesson in db.Lessons)
{
Console.WriteLine($"Lesson: id: {lesson.LessonId}, name: {lesson.Name}");
}
Console.WriteLine();
Console.WriteLine("Students:");
foreach (var student in db.Students)
{
Console.WriteLine($"Student: id: {student.StudentId}, name: {student.Name}");
}
Console.WriteLine();
Console.WriteLine("Enrollments:");
foreach (var enrollment in db.Enrollments)
{
Console.WriteLine($"Enrollment: id: {db.Entry(enrollment).Metadata.FindPrimaryKey()}");
}
}
}
public static void Run()
{
using (var db = new ManyToManyDatabase())
{
Lesson science = new Lesson {
Name = "Science"
};
Lesson math = new Lesson {
Name = "Math"
};
Lesson boring = new Lesson {
Name = "Other Boring Stuff"
};
Student jamie = new Student {
Name = "Jamie"
};
Student chris = new Student {
Name = "Chris"
};
Student danny = new Student {
Name = "Danny"
};
List <Enrollment> enrollments = new List <Enrollment>();
enrollments.Add(new Enrollment {
Student = jamie, Lesson = science
});
enrollments.Add(new Enrollment {
Student = jamie, Lesson = math
});
enrollments.Add(new Enrollment {
Student = chris, Lesson = math
});
enrollments.Add(new Enrollment {
Student = chris, Lesson = boring
});
enrollments.Add(new Enrollment {
Student = danny, Lesson = boring
});
enrollments.Add(new Enrollment {
Student = danny, Lesson = science
});
db.Lessons.Add(science);
db.Lessons.Add(math);
db.Lessons.Add(boring);
db.Students.Add(jamie);
db.Students.Add(chris);
db.Students.Add(danny);
db.Enrollments.AddRange(enrollments);
db.SaveChanges();
}
RenameWithoutChangingContext t1 = new RenameWithoutChangingContext(new ManyToManyDatabase());
RenameWithoutChangingContext t2 = new RenameWithoutChangingContext(new ManyToManyDatabase());
Console.WriteLine("Before any shenanigans");
t1.PrintIt();
t2.PrintIt();
Console.WriteLine();
Console.WriteLine("================================");
Console.WriteLine("Changing name under one context");
t1.SetIt("new name");
Console.WriteLine();
Console.WriteLine("After shenanigans");
t1.PrintIt();
t2.PrintIt();
Console.WriteLine();
Console.WriteLine("================================");
Console.WriteLine();
Console.WriteLine("Before removing student (without loading enrollments):");
PrintDatabase();
using (var db = new ManyToManyDatabase())
{
db.Remove(db.Students.Where(s => s.StudentId == 2).First());
db.SaveChanges();
}
Console.WriteLine();
Console.WriteLine("After removing student (without loading enrollments):");
PrintDatabase();
Console.WriteLine();
Console.WriteLine("================================");
Console.WriteLine();
Console.WriteLine("Before removing student (WITH loading enrollments):");
PrintDatabase();
using (var db = new ManyToManyDatabase())
{
db.Remove(db.Students.Where(s => s.StudentId == 1).Include(s => s.Enrollments).First());
db.SaveChanges();
}
Console.WriteLine();
Console.WriteLine("After removing student (WITH loading enrollments):");
PrintDatabase();
Console.WriteLine();
using (var db = new ManyToManyDatabase())
{
Console.WriteLine("Remaining student:");
foreach (var student in db.Students.Include(s => s.Enrollments).ThenInclude(e => e.Lesson).ToList())
{
Console.WriteLine($" Name: {student.Name}");
foreach (var lesson in student.Enrollments.Select(e => e.Lesson))
{
Console.WriteLine($" Lesson: {lesson.Name}");
}
}
}
Console.ReadLine();
}
public RenameWithoutChangingContext(ManyToManyDatabase db)
{
_db = db;
}