LinqToSQL

//查詢所有的信息并显示新的字段
        static void ObjectQuery()
        {
            var db =new NorthwindDataContext();
            var result = from b in db.Company from c in db.BaseData2s select new { c.EngName, b.ChiName };
            foreach (var item in result)
            {
                Console.WriteLine(item);
            }
            Console.Read();
        }
        //添加数据
        static void AddData()
        {
            var db = new NorthwindDataContext();
            int count = db.Company.Where(c => c.ChiName == "123").Count();
            Console.WriteLine("state:{0}",count);
            var newCompary = new Company() { ChiName="123",ID=888 };
            db.Company.InsertOnSubmit(newCompary);
            db.SubmitChanges();
            int count2 = db.Company.Where(c => c.ChiName == "123").Count();
            Console.WriteLine("state:{0}", count2);
            Console.Read();
        }
        //更新数据
        static void ModifyData()
        {
            var db = new NorthwindDataContext();
            int count = db.Company.Where(c => c.ChiName == "456").Count();
            Console.WriteLine(count);
            var company = db.Company.FirstOrDefault();
            company.ChiName = "456";
            db.SubmitChanges();
            int count2 = db.Company.Where(c => c.ChiName == "456").Count();
            Console.WriteLine(count2);
            Console.Read();
        }
        //数据排序
        static void OrderQuery()
        {
            var db = new NorthwindDataContext();
            var result=from b in db.BaseData2s orderby b.ID descending select new {b.ChiName,b.ID};
            foreach (var item in result)
            {
                Console.WriteLine(item);
            }
        }
        //数据分组
        static void GroupData()
        {
            var db = new NorthwindDataContext();
            var result = from b in db.BaseData2s group b by b.ChiName into g orderby g.Count() select new {num=g.Count(),chiname=g.Key };
            foreach (var item in result)
            {
                Console.WriteLine(item);
            }
        }