EneityFrame Key로 Delete하기

EntityFrameWork를 사용하여 Delete하기 

using (clscEntities context = new clscEntities())
            ｛                
                foreach (var item in input)
                ｛
                    tcl_process_category_study model = new tcl_process_category_study
                    ｛
                        category_no = item.CategoryNo,
                        company_seq = companySeq,                        
                        study_cd = item.ProcessCd,
                        study_type = item.StudyType
                    };
                    context.tcl_process_category_study.Attach(model);
                    context.ObjectStateManager.ChangeObjectState(model, EntityState.Deleted);
                }
                context.SaveChanges();
            }