DataSet设置关系,级联更新、删除,

            DataSet ds = new DataSet();

            DataTable dt1 = new DataTable();
            dt1.Columns.Add("id", typeof(int));
            dt1.Columns.Add("Name", typeof(string));
            dt1.PrimaryKey = new DataColumn[] 
            { 
                dt1.Columns["id"]
            };

            DataTable dt2 = new DataTable();
            dt2.Columns.Add("id", typeof(int));
            dt2.Columns.Add("Mark", typeof(int));
            dt2.Columns.Add("Course", typeof(String));
            dt2.Columns.Add("stuID", typeof(int));

            ds.Tables.Add(dt1);
            ds.Tables.Add(dt2);

            //创建关系
            DataRelation rel=
                ds.Relations.Add(dt1.Columns["id"], dt2.Columns["stuID"]);
            //获取关系的外键
            ForeignKeyConstraint fkc=rel.ChildKeyConstraint;
            //设置级联规则
            fkc.UpdateRule = Rule.None;
            fkc.DeleteRule = Rule.None;

            dt1.Rows.Add(new object[] { 1, "张三" });
            dt1.Rows.Add(new object[] { 2, "李四" });

            dt2.Rows.Add(new object[] { 1, 80,"语文", 1 });
            dt2.Rows.Add(new object[] { 2, 90, "语文", 2 });
            dt2.Rows.Add(new object[] { 3, 60,"数学", 1 });
            dt2.Rows.Add(new object[] { 4, 50, "数学",2 });

            foreach (DataRow dr in dt1.Rows)
            {
                Console.WriteLine(dr["Name"]);
                /*GetChildRows方法用于获取与该行数据关联的子表数据
                *与其相关的还有*/
                foreach (DataRow cdr in dr.GetChildRows(rel))
                {
                    Console.WriteLine("{0}:{1}",
                        cdr["Course"], cdr["Mark"]);
                }
            }