//创建一个UserInfo的数据表

            DataTable dt = new DataTable("UserInfo");

            //添加id和username列

            dt.Columns.Add("id");

            dt.Columns.Add("username");

            //创建行

            DataRow dr = dt.NewRow();

            dr["id"] = 1;

            dr["username"] = "张三";

            dt.Rows.Add(dr);



            DataRow dr1 = dt.NewRow();

            dr1["id"] = 2;

            dr1["username"] = "李四";

            dt.Rows.Add(dr1);



            dt.Rows.Add("3", "王五");



 DataTable detailInfo = new DataTable("detailInfo");

            detailInfo.Columns.Add("ID");

            detailInfo.Columns.Add("phoneNumber");

            detailInfo.Columns.Add("addRess");



            detailInfo.Rows.Add("1", "135XXXX", "北京");

            detailInfo.Rows.Add("2", "136XXXX", "上海");

            detailInfo.Rows.Add("5", "186XXXX", "广州");



            Console.WriteLine("2个表进行合并");



            var query = from t1 in dt.AsEnumerable()

                        join t2 in detailInfo.AsEnumerable()

                        on t1.Field<string>("id") equals t2.Field<string>("ID")

                        select new

                            {

                                id = t1.Field<string>("id"),

                                username = t1.Field<string>("username"),

                                phoneNumber = t2.Field<string>("phoneNumber"),