SQL : select level from dual connect by level <= 100 ;
this generates 100 rows of numbers 1..100. But row generators aren't limited to numbers.
By using date arithmetic, you can generate dates:
select date '2015-01-01' + level -1 as gendate from dual
connect by date '2015-01-01' + level -1 < date '2015-02-01' ;
31 rows selected.
Or by using ASCII codes, you can generate characters:
select chr(65 + level - 1) as letter from dual connect by level <= 26;LETT----
26 rows selected.