Input: N = 20
Query In Oracle:
select rpad('*', level*2, ' *') from dual connect by level <= 20;
Here level refer to N = 20, you can change according to you.
Query In MySql:
with tree (number) AS ( select 1 AS nr UNION ALL select number+1 AS nr FROM tree WHERE number <= 19 ) select REPLICATE('* ',number) from tree Order by number desc