Using Linq to update a database

Coursework new_course_work = new Coursework(); //new coursework
            new_course_work.Due_Date = this.dateTimePicker1.Value;//store selected date as due date
            new_course_work.Title = this.textBox1.Text;//store title from user entry
            new_course_work.Module_Code = moduleList.GetItemText(moduleList.SelectedItem);
            //store module from selection

            Globals.database.Courseworks.InsertOnSubmit(new_course_work);
            Globals.database.SubmitChanges();//submit the new coursework to database

            var query_ = from DataClasses1 in Globals.database.Enrols
                         where DataClasses1.Module_Code == new_course_work.Module_Code
                         select new {DataClasses1.Student_ID };//select every student ID registered on the module
            foreach (var item in query_)
            {
                Submission new_submission = new Submission();
                new_submission.Bar_Ref_ID = Globals.Bar_Ref_Gen(); //a newlyy generated bar ref ID 
                new_submission.CWRefID = new_course_work.CWRefID; //the CWRef ID is same as the original cw
                new_submission.Status = false; //the submission status is initially set at false
                new_submission.Student_ID = item.Student_ID;//the student ID is set for it

                Globals.database.Submissions.InsertOnSubmit(new_submission);
                Globals.database.SubmitChanges();//submit the new submission