static void Main(string[] args)

        {

            DataTable dt1 = new DataTable();

            dt1.Columns.Add("id", typeof(int));

            dt1.Columns.Add("name", typeof(string));

            DataTable dt2 = new DataTable();

            dt2.Columns.Add("id", typeof(int));

            dt2.Columns.Add("sex", typeof(string));

            for (int i = 0; i < 3; i++)

            {

                DataRow dr = dt1.NewRow();

                dr["id"] = i;

                dr["name"] = "table1 " + i;

                dt1.Rows.Add(dr);

            }

            for (int i = 1; i < 4; i++)

            {

                DataRow dr = dt2.NewRow();

                dr["id"] = i;

                dr["sex"] = "sex  " + i;

                dt2.Rows.Add(dr);

            }

            //var q = dt1.AsEnumerable().Join(dt2.AsEnumerable(), dt1key => dt1key.Field<int>("id"),

            //            dt2key => dt2key.Field<int>("id"), (dt1key, dt2key) => new

            //{

            //    id = dt1key.Field<int>("id"),

            //    name = dt1key.Field<string>("name"),

            //    sex = dt2key.Field<string>("sex") 

            //});

            var q = from member in dt1.AsEnumerable()

                    join club in dt2.AsEnumerable() on member.Field<int>("id") equals club.Field<int>("id")