select p;

    q.Dump();

//查询

    var w= from p in Products

           where p.CateoryId==1

           select new {p.ProductName,p.UnitPrice};

    w.Dump();

//按照是否供应分组，显示数量

    var hh= from p in Products

           group p by p.IsAbord into g

           select new {g.Key,Nums=g.Count()};

//按类别分组，显示数量

    var ww= from p in Products

           group p by p.Category.CategoryName into g

           select new {g.Key,Nums=g.Count()};

//阻抗失调,所有数据文件都用from读写

    var xml=new XElement("Products",

          from p in Products

          select new XElement("Product",

          new XElement("ProductName",p.ProductName),

          new XElement("UnitPrice",p.UnitPrice),

          new XAttribute("Category",p.Category.CategoryName))

          );

    xml.Dump();

    xml.Save(@"E:\Products.xml");

//XML文档查询

xml.Elements("Product").Where(e=>e.Element("ProductName").Value.Contains("肉")).Dump();//XML代表根节点

//新增

    Shipper s=new Shipper{ShipperName="EMS",Tel="010-12345678"};

    Shippers.InsertOnSubmit(s);

    SubmitChanges();

//修改

    Shippers.FirstOrDefault(s=>s.ShipperId==5).ShipperName="EMSEMS";

    SubmitChanges();

//删除

    Shipper sss=Shippers.FirstOrDefault(sh=>sh.ShipperId==6);

    Shippers.DeleteOnSubmit(sss);

    SubmitChanges();

//批量删除

    var qq=Shippers.Where(sq=>sq.ShipperId>=3);

    Shippers.DeleteAllOnSubmit(qq);

// Define other methods and classes here