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  • Linq学习比较第2篇

     Linq学习比较第2篇

         参考程序:

                //
                t_User user = new t_User();
                user.UserName 
    = "大气象";
                user.Pwd 
    = "123456";
                ctx.t_User.InsertOnSubmit(user);
    //以前的方法是Add();
                ctx.SubmitChanges();

                
    //
                
    //参考这样的语法string s = (from a in ctx.Customers select a).Single(a => a.ID == 2);
                t_User userUpdate = ctx.t_User.SingleOrDefault(t_User => t_User.ID == 2);//Single与SingleOrDefault没区别
                userUpdate.UserName = "大气象1";
                ctx.SubmitChanges();

                
    //
                t_User userDelete = (from userinfo in ctx.t_User where userinfo.ID == 1 select userinfo).FirstOrDefault();
                
    if (userDelete != null)
                {
                    ctx.t_User.DeleteOnSubmit(userDelete);
                    ctx.SubmitChanges();
                }
         自己的程序:

           //插入
                NorthwindDataContext dc = new NorthwindDataContext(@"Data Source=.\SQLEXPRESS;AttachDbFilename='c:\documents and settings\administrator\my documents\visual studio 2010\Projects\test\test\test.mdf';Integrated Security=True;User Instance=True");
                studentInfo stuInfo = new studentInfo();
                stuInfo.StudentName = "陈小春";
                stuInfo.studentAge = 35;
                dc.studentInfo.InsertOnSubmit(stuInfo);
                dc.SubmitChanges();
                //修改
                studentInfo updateInfo = dc.studentInfo.SingleOrDefault(studentInfo => studentInfo.studentid == 2);
                updateInfo.StudentName = "刘德华";
                dc.SubmitChanges();
                //删除
                studentInfo deleteInfo = (from userinfo in dc.studentInfo where userinfo.studentid == 1 select userinfo).SingleOrDefault();
                if(deleteInfo!=null)
                {
                    dc.studentInfo.DeleteOnSubmit(deleteInfo);
                    dc.SubmitChanges();
                }
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  • 原文地址:https://www.cnblogs.com/wangyhua/p/4050646.html
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