public bool NewCourse(string Name, int IsElective, int Credit)
{
try
{
using (var context = new course_selectionContext())
{
var data = new CourseDb();
int newid = context.CourseDb.ToList().Count() == 0 ? 1 : context.CourseDb.ToList().Max(x => x.Code) + 1;
data.Code = newid;
data.Name = Name;
data.IsElective = IsElective;
data.Credit = Credit;
context.CourseDb.Add(data);
context.SaveChanges();
Console.WriteLine("新课程的课程编号为：" + newid);
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return(false);
}
return(true);
}
public bool Delete(int id)
{
try
{
using (var context = new course_selectionContext())
{
var data = context.StudentDb.Where(x => x.Id == id).FirstOrDefault();
context.StudentDb.Remove(data);
context.SaveChanges();
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return(false);
}
return(true);
}
public bool Change(int id, string Name, string Class)
{
try
{
using (var context = new course_selectionContext())
{
var data = context.StudentDb.First(x => x.Id == id);
data.Name = Name;
data.Class = Class;
context.SaveChanges();
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return(false);
}
return(true);
}
public bool Change(int id, string Name, int IsElective, int Credit)
{
try
{
using (var context = new course_selectionContext())
{
var data = context.CourseDb.First(x => x.Code == id);
data.Credit = Credit;
data.IsElective = IsElective;
data.Name = Name;
context.SaveChanges();
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return(false);
}
return(true);
}
public bool Delete(int id)
{
try
{
using (var context = new course_selectionContext())
{
var data = context.CourseDb.Where(x => x.Code == id).FirstOrDefault();
if (data.IsElective == 1 && data.StudentCourseMaping != null)
{
throw new Exception("已有学生选修该选修课程，无法删除");
}
context.CourseDb.Remove(data);
context.SaveChanges();
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return(false);
}
return(true);
}
public bool Delete(int CourseId, int StudentId)
{
try
{
using (var context = new course_selectionContext())
{
var data = context.StudentCourseMaping.Where(x => x.CourseId == CourseId && x.StudentId == StudentId).FirstOrDefault();
if (data == null)
{
throw new Exception("信息有误");
}
context.StudentCourseMaping.Remove(data);
context.SaveChanges();
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return(false);
}
return(true);
}
public bool select(int CourseId, int StudentId)
{
try
{
using (var context = new course_selectionContext())
{
if (context.StudentDb.Where(x => x.Id == StudentId).ToList().Count() == 0)
{
throw new Exception("学生不存在");
}
if (context.CourseDb.Where(x => x.Code == CourseId).ToList().Count() == 0)
{
throw new Exception("课程不存在");
}
if (context.StudentCourseMaping.Where(x => x.CourseId == CourseId && x.StudentId == StudentId).Count() != 0)
{
throw new Exception("不允许重复选课");
}
var data = new StudentCourseMaping();
int id = context.StudentCourseMaping.ToList().Count() == 0 ? 1 : context.StudentCourseMaping.ToList().Max(x => x.Id) + 1;
data.Id = id;
data.StudentId = StudentId;
data.CourseId = CourseId;
context.StudentCourseMaping.Add(data);
context.SaveChanges();
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return(false);
}
return(true);
}
public bool NewStudent(string Name, string Class)
{
try
{
using (var context = new course_selectionContext())
{
var data = new StudentDb();
int newid = context.StudentDb.ToList().Count() == 0 ? 1 : context.StudentDb.ToList().Max(x => x.Id) + 1;
data.Id = newid;
data.Name = Name;
data.Class = Class;
context.StudentDb.Add(data);
context.SaveChanges();
Console.WriteLine("添加学生的学生编号为：" + newid);
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
return(false);
}
return(true);
}