Linq to SQL 练习

public class HomeController : Controller
    {
        //
        // GET: /Home/
        empentity entity = new empentity();
        public ActionResult Index()
        {
            List<EmpCount> lst = (from m in entity.emp.ToList()
                                  join n in entity.dept.ToList() on m.DEPTNO equals n.DEPTNO
                                  group m by m.DEPTNO into newEmp
                                  select new EmpCount
                                  {
                                      DeptID = newEmp.Key,
                                      DName = entity.dept.Where(p => p.DEPTNO == newEmp.Key).FirstOrDefault().DNAME,
                                      Count = newEmp.Count()
                                  }).ToList();
                               
                                
            return View(lst);
        }
        public ActionResult SelSal()
        {
            List<emp> lst = (from s in entity.emp.ToList()
                            select s).ToList();
            return View(lst);
        }
        public ActionResult SelEmpSal()
        {
            ViewBag.SalgradeId = new SelectList(entity.salgrade.ToList(), "SalgradeId", "GRADE");
            return View(entity.emp.ToList());
        }
        [HttpPost]
        public ActionResult SelEmpSal(int SalgradeId)
        {
            ViewBag.SalgradeId = new SelectList(entity.salgrade.ToList(), "SalgradeId", "GRADE");
            Salgrade lst = (from s in entity.salgrade.ToList()
                    where s.SalgradeId == SalgradeId
                    select s).FirstOrDefault();
            int Max = lst.HISAL;
            int Min = lst.LOSAL;
            List<emp> lst1 = (from m in entity.emp.ToList()
                             where m.SAL > Min && m.SAL < Max
                             select m).ToList();
            return View("SelEmpSal", lst1);

        }
        public ActionResult EmpSal1()
        {
            Salgrade sal = (from s in entity.salgrade.ToList()
                           where s.GRADE.Contains("二级")
                           select s).FirstOrDefault();
            int Max = sal.HISAL;
            int Min = sal.LOSAL;
            List<emp> lst = (from i in entity.emp.ToList()
                            where i.SAL > Min && i.SAL < Max
                            select i).ToList();
            return View(lst);
        }
        public ActionResult EmpCount()
        { 
            Salgrade sal = (from s in entity.salgrade.ToList()
                           where s.GRADE.Contains("一级")
                           select s).FirstOrDefault();
            int Max = sal.HISAL;
            int Min = sal.LOSAL;
            List<EmpCount> count = (from m in entity.emp.ToList()
                                    join n in entity.dept.ToList() on m.DEPTNO equals n.DEPTNO
                                    where m.SAL > Min && m.SAL < Max
                                    group m by m.DEPTNO into newEmp
                                    select new EmpCount
                                    {
                                        DeptID = newEmp.Key,
                                        DName = entity.dept.Where(p => p.DEPTNO == newEmp.Key).FirstOrDefault().DNAME,
                                        Count = newEmp.Count()
                                    }).ToList();
            return View(count);
        }
        public ActionResult EmpSal2()
        {
            Salgrade sal = (from s in entity.salgrade.ToList()
                            where s.GRADE == "二级"
                            select s).FirstOrDefault();
            int Max = sal.HISAL;
            int Min = sal.LOSAL;
            List<emp> lst = (from i in entity.emp.ToList()
                             where i.SAL > Min && i.SAL < Max
                             select i).ToList();
            return View(lst);
        }
        public ActionResult EmpCount1()
        {
            Salgrade sal = (from s in entity.salgrade.ToList()
                            where s.GRADE == "一级"
                            select s).FirstOrDefault();
            int Max = sal.HISAL;
            int Min = sal.LOSAL;
            List<EmpCount> lst = (from m in entity.emp.ToList()
                                  join n in entity.dept.ToList() on m.DEPTNO equals n.DEPTNO
                                  where m.SAL>Min&&m.SAL<Max
                                  group m by m.DEPTNO into newEmp
                                  select new EmpCount
                                  {
                                      DeptID = newEmp.Key,
                                      DName = entity.dept.Where(p => p.DEPTNO == newEmp.Key).FirstOrDefault().DNAME,
                                      Count = newEmp.Count()
                                  }).ToList();
            return View(lst);
        }
        public ActionResult EmpLd()
        {
            List<emp> lst = (from n in entity.emp.ToList()
                            join m in entity.emp.ToList() on n.EMPNO equals m.MGR
                             select n).Distinct().ToList();
            ViewBag.DEPTNO = new SelectList(entity.dept.ToList(), "DEPTNO", "DNAME");
            ViewBag.SalgradeId = new SelectList(entity.salgrade.ToList(), "SalgradeId", "GRADE");
            return View(lst);
        }
        [HttpPost]
        public ActionResult EmpLd1(int DEPTNO, int SalgradeId)
        {
            ViewBag.DEPTNO = new SelectList(entity.dept.ToList(), "DEPTNO", "DNAME");
            ViewBag.SalgradeId = new SelectList(entity.salgrade.ToList(), "SalgradeId", "GRADE");
            Salgrade sal = entity.salgrade.Find(SalgradeId);
            int Max = sal.HISAL;
            int Min = sal.LOSAL;
            List<emp> lst = (from n in entity.emp.ToList()
                             join m in entity.emp.ToList() on n.EMPNO equals m.MGR
                             where n.SAL > Min && n.SAL < Max && n.DEPTNO == DEPTNO
                             select n).Distinct().ToList();
            foreach (emp item in lst)
            {
                emp s = entity.emp.Find(item.EMPNO);
                s.SAL = item.SAL + 2000;
            }
            entity.SaveChanges();
            return RedirectToAction("EmpLd");
        }
        public ActionResult EmpLd2()
        {
            List<emp> ld = (from m in entity.emp.ToList()
                            join n in entity.emp.ToList() on m.EMPNO equals n.MGR
                            select m).Distinct().ToList();
            ViewBag.DEPTNO = new SelectList(entity.dept.ToList(), "DEPTNO", "DNAME");
            ViewBag.SalgradeId = new SelectList(entity.salgrade.ToList(), "SalgradeId", "GRADE");
            return View(ld);
        }
        [HttpPost]
        public ActionResult EmpLd3(int DEPTNO, int SalgradeId)
        {
            ViewBag.DEPTNO = new SelectList(entity.dept.ToList(), "DEPTNO", "DNAME");
            ViewBag.SalgradeId = new SelectList(entity.salgrade.ToList(), "SalgradeId", "GRADE");
            Salgrade sal = entity.salgrade.Find(SalgradeId);
            List<emp> lst = (from n in entity.emp.ToList()
                            join m in entity.emp.ToList() on n.EMPNO equals m.MGR
                            where n.SAL > sal.LOSAL && n.SAL < sal.HISAL && n.DEPTNO == DEPTNO
                            select n).Distinct().ToList();
            foreach (emp item in lst)
            {
                emp s = entity.emp.Find(item.EMPNO);
                s.SAL = item.SAL + 2000;
            }
            entity.SaveChanges();
            return RedirectToAction("EmpLd2");
        }
    }