/// <summary>
/// Commits the courses, that were moved to the
/// pre-reqs listview, to the preReqs table
/// </summary>
public void CommitPreReqs()
{
try
{
using (var context = new SchoolU_DBEntities())
{
// Gets all the courses names
IList <string> allCourseName = context.Courses.Where(i => i.CourseId != 0).Select(i => i.CourseName).ToList();
// Gets the course id for the course that was recently added
int courseAdded = context.Courses.Where(i => i.CourseName == CourseName).Select(i => i.CourseId).Single();
if (SelectedCourseCollection.Any())
{
// Stores the PreRequisite objects so they can be added all at the same time using the AddRange method
IList <PreRequisite> PreReqList = new List <PreRequisite>();
if (IsPreReqListDifferent())
{
for (int i = 0; i < GetPreReqIds().Count; i++)
{
var newPreReq = new PreRequisite()
{
CourseId = courseAdded,
PrereqId = GetPreReqIds().ElementAt(i)
};
PreReqList.Add(newPreReq);
}
context.PreRequisites.AddRange(PreReqList);
}
context.SaveChanges();
}
}
}
catch (Exception ex)
{
//MessageBox.Show(ex.Message);
return;
}
}
/// <summary>
/// Gets a list of course Ids based on the pre-req names
/// currently in the pre-reqs list (SelectedCourseCollection)
/// </summary>
/// <returns></returns>
public IList <int> GetPreReqIds()
{
IList <int> preReqIds = new List <int>();
try
{
using (var context = new SchoolU_DBEntities())
{
if (SelectedCourseCollection.Any())
{
// Gets all the pre-req courses names
IList <string> pre_reqNames = SelectedCourseCollection.Where(i => i.CourseName != string.Empty).Select(i => i.CourseName).ToList();
// Gets all the course ids off of the courses names added to the pre-reqs list // pre-req = course ids
return(preReqIds = context.Courses.Where(i => pre_reqNames.Contains(i.CourseName)).Select(i => i.CourseId).ToList());
}
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
return(null);
}
return(null);
}