mysql> drop table if exists  tmp_tbl;
Query OK,  0  rows affected ( 0 . 02  sec)

mysql> set @stm='create table tmp_tbl ( ', @ins='insert into tmp_tbl values (';
Query OK,  0  rows affected ( 0 . 00  sec)

mysql>
mysql> select count(*)
    -> into @r_count
    -> from
    -> (
    -> select
    ->   @stm:=concat(@stm,concat(concat('col', id),' int,')),
    ->   @ins:=concat(@ins,concat(id,','))
    -> from for_tree_tbl
    -> ) no_results_to_client_tbl;
Query OK,  1  row affected ( 0 . 00  sec)

mysql>
mysql>
mysql> set @stm:=concat(@stm,'end_col int) engine=memory'),@ins:=concat(@ins,concat(@r_count,')'));
Query OK,  0  rows affected ( 0 . 00  sec)

mysql>
mysql> prepare c_tbl_stm from @stm;
Query OK,  0  rows affected ( 0 . 00  sec)
Statement prepared

mysql>
mysql> execute c_tbl_stm;
Query OK,  0  rows affected ( 0 . 08  sec)

mysql>
mysql> deallocate prepare c_tbl_stm;
Query OK,  0  rows affected ( 0 . 00  sec)

mysql>
mysql> prepare i_data_stm from @ins;
Query OK,  0  rows affected ( 0 . 00  sec)
Statement prepared

mysql>
mysql> execute i_data_stm;
Query OK,  1  row affected ( 0 . 00  sec)

mysql>
mysql> deallocate prepare i_data_stm;
Query OK,  0  rows affected ( 0 . 00  sec)

mysql>
mysql> select * from tmp_tbl;
+------+------+------+------+------+------+---------+
| col1 | col2 | col3 | col4 | col5 | col6 | end_col |
+------+------+------+------+------+------+---------+
|     1  |     2  |     3  |     4  |     5  |     6  |        6  |
+------+------+------+------+------+------+---------+
 1  row in set ( 0 . 00  sec)

mysql>