public SwapOperation(Form1 form, ArrayList _students, CoursemoEntities _db)
{
InitializeComponent();
form1 = form;
students = _students;
db = _db;
}
//display information about each course that was selected
//course can be selected on any listbox that are displayed
//registered courses available courses and waitlist courses
private void selectCourse(string clas)
{
using (var db = new CoursemoEntities())
{
try
{
string[] values = clas.Split(' ');
int crn = Convert.ToInt32(values[3]);
var c = (from a in db.Classes
join s in db.Semesters
on a.Semester equals s.SMID
join t in db.ClassTypes
on a.CTID equals t.CTID
where a.CRN == crn
select new
{
SEMESTER = s.Semester1,
YEAR = a.Years,
TYPE = t.ClassType1,
DAY = a.WeekDays,
TIME = a.Times,
SIZE = a.Capcity,
CURENTENROLMENT = a.CurrentTotal,
WAIT = a.CID
}).ToArray();
this.textBoxDay.Text = c[0].DAY;
this.textBoxSemester.Text = c[0].SEMESTER;
this.textBoxSize.Text = c[0].SIZE.ToString();
this.textBoxType.Text = c[0].TYPE;
this.textBoxYear.Text = c[0].YEAR.ToString();
this.textBoxTime.Text = c[0].TIME;
this.textBoxCurrentEnrolment.Text = c[0].CURENTENROLMENT.ToString();
int cid = c[0].WAIT;
var x = (from i in db.StudentWaitLists
where i.CID == cid
select i).Count();
this.textBoxWaitList.Text = x.ToString();
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
}
}
//-------------------------------------------------------------------------------------------------------
//load new form to perform swap
private void button5_Click(object sender, EventArgs e)
{
using (var db = new CoursemoEntities())
{
var box = new SwapOperation(this, students, db);
box.StartPosition = FormStartPosition.CenterParent;
box.ShowDialog();
try
{
getStudentLists();
getWaitAndEnrolmentLists();
}
catch (Exception ex) { Console.WriteLine(ex); }
}
}
//-------------------------------------------------------------------------------------------------------
//reset DB to original state where registration is 0
private void fILEToolStripMenuItem_Click(object sender, EventArgs e)
{
using (var db = new CoursemoEntities())
{
//remove from students classes
var clases = from s in db.StudentClasses
select s;
foreach (var p in clases)
{
db.StudentClasses.Remove(p);
}
//remove from studen waitlist
var waitList = from s in db.StudentWaitLists
select s;
foreach (var p in waitList)
{
db.StudentWaitLists.Remove(p);
}
var query = from a in db.Classes
select a;
foreach (var p in query)
{
p.CurrentTotal = 0;
}
try
{
db.SaveChanges();
getStudentLists();
getWaitAndEnrolmentLists();
}
catch (Exception ex)
{
Console.WriteLine(ex);
clearGui();
}
MessageBox.Show("DATABASE WAS RESET");
try
{
getWaitAndEnrolmentLists();
}
catch (Exception ex) { Console.WriteLine(ex); }
}
}
//when form loads create arraylists of students and classes
//that are available in DB
private void Form1_Load(object sender, EventArgs e)
{
//db = new CoursemoEntities();
students = new ArrayList();
classes = new ArrayList();
using (var db = new CoursemoEntities())
{
foreach (Student s in db.Students)
{
students.Add(s);
}
foreach (var clas in db.Classes)
{
classes.Add(clas);
}
}
}
//-------------------------------------------------------------------------------------------------------
//display list of netids in the list boxes for the
//registered student and student thta are on wait list
private void getWaitAndEnrolmentLists()
{
this.listBoxWaitList.Items.Clear();
this.listBoxEnrolment.Items.Clear();
//check students on the wait list and display netid
selectCourse(this.listBoxAvailableCourses.Text);
int i = this.listBoxAvailableCourses.SelectedIndex;
Class myCLass = (Class)classes[i];
int cid = myCLass.CID;
using (var db = new CoursemoEntities())
{
var query = (from a in db.StudentWaitLists
join b in db.Students
on a.STID equals b.STID
where a.CID == cid
select new
{
NETID = b.NetID
}).ToList();
foreach (var p in query)
{
this.listBoxWaitList.Items.Add(p.NETID);
}
//make a list registered studetnts for selected class
query = (from a in db.StudentClasses
join b in db.Students
on a.STID equals b.STID
where a.CID == cid
select new
{
NETID = b.NetID
}).ToList();
foreach (var p in query)
{
this.listBoxEnrolment.Items.Add(p.NETID);
}
}
}
//display all courses that are offered for registration
private void buttonCourses_Click(object sender, EventArgs e)
{
this.listBoxAvailableCourses.Items.Clear();
using (var db = new CoursemoEntities())
{
var c = (from a in db.Classes
join dep in db.Departments
on a.DID equals dep.DID
select new
{
Dep = dep.Department1,
CLASS = a.ClassNum,
CReN = a.CRN
}).ToList();
foreach (var p in c)
{
string clas = string.Format(@"{0}{1} --> CRN#: {2}", p.Dep, p.CLASS, p.CReN);
this.listBoxAvailableCourses.Items.Add(clas);
}
}
}
//main function to updating students list do all operation on
//each student
private void getStudentLists()
{
clearGui();
string netid = this.listBox1.SelectedIndex.ToString();
Student g = (Student)students[this.listBox1.SelectedIndex];
int studentID = g.STID;
this.textBoxNETID.Text = g.NetID;
using (var db = new CoursemoEntities())
{
//get registered classes
var c = (from a in db.Classes
join d in db.StudentClasses
on a.CID equals d.CID
join dep in db.Departments
on a.DID equals dep.DID
join s in db.Students
on d.STID equals s.STID
where a.CID == d.CID
where d.STID == g.STID
select new
{
Dep = dep.Department1,
ID = a.CID,
CLASS = a.ClassNum,
CReN = a.CRN
}).ToList();
foreach (var p in c)
{
string clas = string.Format(@"{0}{1} --> CRN#: {2}", p.Dep, p.CLASS, p.CReN);
this.listBoxRegitered.Items.Add(clas);
}
//get list of waitlist classes
var wait = (from a in db.Classes
join d in db.StudentWaitLists
on a.CID equals d.CID
join dep in db.Departments
on a.DID equals dep.DID
join s in db.Students
on d.STID equals s.STID
where a.CID == d.CID
where d.STID == g.STID
select new
{
Dep = dep.Department1,
ID = a.CID,
CLASS = a.ClassNum,
CReN = a.CRN
}).ToList();
foreach (var p in wait)
{
string clas = string.Format(@"{0}{1} --> CRN#: {2}", p.Dep, p.CLASS, p.CReN);
this.listBoxWait.Items.Add(clas);
}
}
}
//-------------------------------------------------------------------------------------------------------
//withdraw from wait list using transaction
private void button4_Click(object sender, EventArgs e)
{
if (this.listBoxWait.SelectedItem == null)
{
MessageBox.Show("Select Class you want to drop");
return;
}
string selectedClass = this.listBoxWait.SelectedItem.ToString();
int index = this.listBox1.SelectedIndex;
Student student = (Student)students[index];
int stid = student.STID;
string[] values = selectedClass.Split(' ');
int crn = Convert.ToInt32(values[3]);
int cid = -1;
using (var db = new CoursemoEntities())
{
//begin transaction
using (var trans = db.Database.BeginTransaction())
{
try
{
delay();
var xyz = (from h in db.StudentWaitLists
join i in db.Classes
on h.CID equals i.CID
join s in db.Students
on h.STID equals s.STID
where i.CRN == crn && h.STID == stid
select h).Count();
Console.WriteLine("to jest drop wait x: {0}", xyz);
if (xyz == 0)
{
throw new System.InvalidOperationException("Aready on the list rollback");
}
var query = from a in db.Classes
where a.CRN == crn
select a;
foreach (var p in query)
{
cid = p.CID;
}
var q = from c in db.StudentWaitLists
where c.CID == cid && c.STID == stid
select c;
foreach (var p in q)
{
db.StudentWaitLists.Remove(p);
}
db.SaveChanges();
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
Console.WriteLine(ex);
MessageBox.Show("Rollback");
}
try
{
getStudentLists();
getWaitAndEnrolmentLists();
clearTXTboxes();
}
catch (Exception ex) { Console.WriteLine(ex); }
}
}
}
//-------------------------------------------------------------------------------------------------------
private void button3_Click(object sender, EventArgs e)
{
if (this.listBoxRegitered.SelectedItem == null)
{
MessageBox.Show("Select Class you want to drop");
return;
}
string selectedClass = this.listBoxRegitered.SelectedItem.ToString();
int index = this.listBox1.SelectedIndex;
Student student = (Student)students[index];
int stid = student.STID;
string[] values = selectedClass.Split(' ');
int crn = Convert.ToInt32(values[3]);
int cid = -1;
using (var db = new CoursemoEntities())
{
//begin transaction
using (var trans = db.Database.BeginTransaction())
{
try
{
delay();
//check if registerd on this class for multi-user operation
var xyz = (from h in db.StudentClasses
join i in db.Classes
on h.CID equals i.CID
join s in db.Students
on h.STID equals s.STID
where i.CRN == crn && h.STID == stid
select h).Count();
Console.WriteLine("to jest drop x: {0}", xyz);
//if its not on the list throw exception and rollback transaction
if (xyz == 0)
{
throw new System.InvalidOperationException("Aready on the list rollback");
}
//search class by crn
var query = from a in db.Classes
where a.CRN == crn
select a;
//update current total -1 and get course id
foreach (var p in query)
{
p.CurrentTotal = p.CurrentTotal - 1;
cid = p.CID;
}
//find student in sthe classes registered and remove
var q = from c in db.StudentClasses
where c.CID == cid && c.STID == stid
select c;
foreach (var p in q)
{
db.StudentClasses.Remove(p);
}
//now find if someone on the wait list if so remove from waitlist
//and add to registered
var x = -1;
try
{
x = (from s in db.StudentWaitLists
where s.CID == cid
select s).Min(c => c.SCID);
}
catch (Exception ex)
{
Console.WriteLine(ex);
x = -1;
}
//if x =-1 no one on the wait list ignore and coninue
if (x == -1)
{
Console.WriteLine("wait list is empty ");
}
//else create new student and put on the list
else
{
var h = from s in db.StudentWaitLists
where s.SCID == x
select new
{
STID = s.STID,
CID = s.CID,
YEARS = s.YEARS
};
StudentClass studentClass = new StudentClass();
foreach (var i in h)
{
studentClass.YEARS = i.YEARS;
studentClass.CID = i.CID;
studentClass.STID = i.STID;
}
//remove from waitlist
var z = from a in db.StudentWaitLists
where a.SCID == x
select a;
foreach (var i in z)
{
db.StudentWaitLists.Remove(i);
}
//update classes curent enrolment
var o = from i in db.Classes
where i.CID == cid
select i;
foreach (var i in o)
{
i.CurrentTotal = i.CurrentTotal + 1;
}
db.StudentClasses.Add(studentClass);
}
db.SaveChanges();
trans.Commit();
}
catch (Exception ex)
{
trans.Rollback();
MessageBox.Show("Rollback");
Console.WriteLine(ex);
}
}
}
//try catch if seleted item is null
try
{
clearTXTboxes();
getStudentLists();
getWaitAndEnrolmentLists();
}
catch (Exception ex)
{
Console.WriteLine(ex);
}
}
//-------------------------------------------------------------------------------------------------------
//register for a course using transaction if fail then will rollback
private void button2_Click(object sender, EventArgs e)
{
if (this.listBox1.SelectedItem == null)
{
MessageBox.Show("Select Student");
return;
}
if (this.listBoxAvailableCourses.SelectedItem == null)
{
MessageBox.Show("Select Class from available courses.");
return;
}
using (var db = new CoursemoEntities())
{
using (var trans = db.Database.BeginTransaction())
{
ArrayList regiteredClasses = new ArrayList();
ArrayList waitList = new ArrayList();
delay();
string selectedClass = this.listBoxAvailableCourses.SelectedItem.ToString();
int index = this.listBox1.SelectedIndex;
int i = this.listBoxAvailableCourses.SelectedIndex;
Student student = (Student)students[index];
Class myClass = (Class)classes[i];
StudentClass studentClass = new StudentClass();
studentClass.YEARS = myClass.Years;
studentClass.STID = student.STID;
studentClass.CID = myClass.CID;
StudentWaitList studentWaitList = new StudentWaitList();
studentWaitList.YEARS = myClass.Years;
studentWaitList.STID = student.STID;
studentWaitList.CID = myClass.CID;
string[] values = selectedClass.Split(' ');
int crn = Convert.ToInt32(values[3]);
var x = (from c in db.Classes
join s in db.StudentClasses
on c.CID equals s.CID
where c.CRN == crn && s.STID == student.STID
select c).Count();
var y = (from c in db.Classes
join s in db.StudentWaitLists
on c.CID equals s.CID
where c.CRN == crn && s.STID == student.STID
select c).Count();
Console.WriteLine("this is x: {0}", x);
Console.WriteLine("this is y: {0}", y);
try
{
//check is student is on the wait list or class registerd list
//if is on either one cancel transaction
if (x > 0 || y > 0)
{
MessageBox.Show("You are on the list");
throw new System.InvalidOperationException("Aready on the list rollback");
}
//update classes total curretn
var query = from a in db.Classes
where a.CID == studentClass.CID
select a;
foreach (var p in query)
{
//if current enrolled equals capacity put student on the wait list
if (p.CurrentTotal == p.Capcity)
{
db.StudentWaitLists.Add(studentWaitList);
}
//else put on the registered list and update db
else
{
p.CurrentTotal = p.CurrentTotal + 1;
db.StudentClasses.Add(studentClass);
}
}
db.SaveChanges();
db.Database.CurrentTransaction.Commit();
}
catch (Exception ex)
{
trans.Rollback();
MessageBox.Show("rollback");
Console.WriteLine(ex);
}
}
}
//update gui
getStudentLists();
getWaitAndEnrolmentLists();
selectCourse(this.listBoxAvailableCourses.Text);
}
