asp.net之C#编程简洁小技巧

 SqlConnection conn = DBFactory.getSqlConn();
            SqlCommand cmd = new SqlCommand();
            string querySql = "SELECT [id], [username], [password] FROM [User] where username = @username";
            cmd.CommandText = querySql;
            cmd.Connection = conn;
             cmd.Parameters.AddWithValue("@username", "樊");
            conn.Open();
            SqlDataReader reader =  cmd.ExecuteReader();
            while (reader.Read())
            {
                Label1.Text = reader["password"].ToString();
            }
            reader.Close();
            conn.Close();



SqlConnection conn = DBFactory.getSqlConn();
            SqlCommand cmd = new SqlCommand();
            string querySql = "SELECT [id], [username], [password] FROM [User] where username = @username";
            cmd.CommandText = querySql;
            cmd.Connection = conn;
             cmd.Parameters.AddWithValue("@username", "樊");

            conn.Open();
            SqlDataAdapter adapter = new SqlDataAdapter(cmd);
            DataSet ds = new DataSet();
            adapter.Fill(ds);
             
             
            foreach (DataRow dr in ds.Tables[0].Rows)
            {
                Response.Write(dr["password"].ToString()+"<br>");
            }
     
            conn.Close();

 //Linq的简单使用
            DBFactoryDataContext context = new DBFactoryDataContext();
           
            //增加
            Student stud1 = new Student();
            stud1.username = "fuck";
            stud1.password = "fuck";
            context.Student.InsertOnSubmit(stud1);
            context.SubmitChanges();
            
            //删除
            var query1 = from student in context.Student where student.username =="小樊" select student;
            foreach (var stu in query1)
            {
                context.Student.DeleteOnSubmit(stu);
            }
            
            //修改
            var query2 = from student in context.Student where student.username == "fuck" select student;
            foreach (var stu in query2)
            {
                stu.password = "funkUpdate";
            }
            context.SubmitChanges();
            
            //查询
            Table<Student> list = context.GetTable<Student>();
            var query3 = from student in list select student;
            foreach (var stu in query3)
            {
                Response.Write(stu.username+"====="+stu.password+"<br>");
            }