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using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace bai1 { class Program { public static NorthwindDataContext dbs = new NorthwindDataContext(); public static void grouping (){ //query var fullMaDia = from p in dbs.T_Dia_Phims select p.MaDia; Console.WriteLine("bang ma dia:"); foreach (var p in fullMaDia) { Console.WriteLine(p); } Console.WriteLine("==============================================="); var maDiaGroupBy = from p in dbs.T_Dia_Phims group p by p.T_Dia; Console.WriteLine("Group by theo ma dia:"); foreach(var g in maDiaGroupBy) { Console.WriteLine(g.Key.MaDia+"\t"+g.Key.TenDia); } } public static void aggregate() { var phimCounts = from p in dbs.T_Phim_DienViens group p by p.MaDienVien into p select new { MaDV = p.Key, soLuongPhimDong = p.Key.Count() }; foreach (var p in phimCounts) { Console.WriteLine(p); } } public static void conversion() { var DV = from p in dbs.T_DienViens select p; Console.WriteLine("bang dien vien:"); foreach (var p in DV) { Console.WriteLine(p.MaDienVien + "\t" + p.TenDienVien); } Console.WriteLine("======================================================="); var sortNameDV = from p in dbs.T_DienViens orderby p.TenDienVien select p; Console.WriteLine("sau khi sap xep theo bang chu cai:"); foreach (var p in sortNameDV) { Console.WriteLine(p.MaDienVien+"\t"+p.TenDienVien); } } public static void ElementOperator() { var DV = from p in dbs.T_DienViens select p; Console.WriteLine("bang dien vien:"); foreach (var p in DV) { Console.WriteLine(p.MaDienVien + "\t" + p.TenDienVien+"\t"+p.QuocTich); } Console.WriteLine("======================================================="); Console.WriteLine("quoc tich VN dau tien"); var fulllVN = from p in dbs.T_DienViens where p.QuocTich == "Việt Nam" select p; var VNfirst= fulllVN.FirstOrDefault(); //lấy phần tử có quốc tịch VN đầu tiên khi query Console.WriteLine(VNfirst.MaDienVien+"\t"+VNfirst.TenDienVien+"\t"+VNfirst.QuocTich); Console.WriteLine("======================================================="); Console.WriteLine("quoc tich my dau tien"); var fulllMy = from p in dbs.T_DienViens where p.QuocTich == "Mỹ" select p; var Myfirst = fulllMy.FirstOrDefault(); //lấy phần tử có quốc tịch Mỹ đầu tiên khi query Console.WriteLine(Myfirst.MaDienVien + "\t" + Myfirst.TenDienVien + "\t" + Myfirst.QuocTich); } public static void joinOpeator() { var customJoin = from p in dbs.T_ThueDias join g in dbs.T_KhachHangs on p.MaKhachHang equals g.MaKhachHang select new { maKH = p.MaKhachHang, tenKH = g.TenKhachHang, diaChi = g.DiaChi, diaThue = p.MaDia }; foreach (var p in customJoin) { Console.WriteLine(p); } } public static void PartitioningOpeator() { //lấy 3 record đầu tiên của bảng var ThreeThueDia = (from p in dbs.T_ThueDias select p).Take(3); foreach (var p in ThreeThueDia) { Console.WriteLine(p.MaDia+"\t"+p.MaKhachHang+"\t"+p.NgayThue+"\t"+p.NgayTra); } Console.WriteLine("======================================"); //bỏ qua 4 record đầu bảng var Skip4ThueDia= (from p in dbs.T_ThueDias select p).Skip(4); foreach (var p in Skip4ThueDia) { Console.WriteLine(p.MaDia + "\t" + p.MaKhachHang + "\t" + p.NgayThue + "\t" + p.NgayTra); } } public static void ProjectionOperator() { var ThueDia = from p in dbs.T_ThueDias where p.MaKhachHang=="KH0002" select new { ngayThue=p.NgayThue,ngayTra=p.NgayTra }; foreach (var p in ThueDia) { Console.WriteLine(p); } } public static void quantifiers() { //tìm diễn viên có vai chính var vaiChinh = from p in dbs.T_Phim_DienViens group p by p.MaDienVien into test where test.All(p => p.VaiChinh == true) select new { maDV = test.Key, soPhimlaDV_Chinh = test.Key.Count() }; //mã diễn viên và số lượng phim mà diễn viên đó đóng vai chính foreach (var p in vaiChinh) { Console.WriteLine(p); } } public static void setOperator() { var maKH = from p in dbs.T_KhachHangs select p.MaKhachHang; var maKHThue = from p in dbs.T_ThueDias select p.MaKhachHang; var unique = maKH.Union(maKHThue); //lấy tất cả ở 2 bảng foreach (var p in unique) { Console.WriteLine(p); } //lấy phần tử chung 2 bảng Console.WriteLine("================================"); var unique2 = maKH.Intersect(maKHThue); foreach (var p in unique2) { Console.WriteLine(p); } } public static void miscellaneous() { var diaID = from c in dbs.T_Dias select c.MaDia; var diaPhimID = from c in dbs.T_Dia_Phims select c.MaDia; var allID = diaID.Concat(diaPhimID); foreach (var p in allID) { Console.WriteLine(p); } } static void Main(string[] args) { //grouping(); //aggregate(); //conversion(); //ElementOperator(); //joinOpeator(); //PartitioningOpeator(); //ProjectionOperator(); //quantifiers(); //setOperator(); miscellaneous(); Console.ReadKey(); } } }
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