I need query to split the string

Question

I need query to split the input string into comma seperated triplets values.
Input String: Database
Output : Dat, ata,tab,aba,bas,ase

Answer 1

SQL> with t
  2  as
  3  (
  4  select 'Database' str
  5    from dual
  6  )
  7  select substr(str, level, 3) str
  8    from t
  9   where length(substr(str, level, 3)) = 3
10  connect by level <= length(str);
STR
Dat
ata
tab
aba
bas
ase
6 rows selected.
And if you want it as a single string then..
SQL> with t
  2  as
  3  (
  4  select 'Database' str
  5    from dual
  6  )
  7  select ltrim(sys_connect_by_path(str, ','), ',') str
  8    from (
  9            select row_number() over(order by level) rno
10                 , substr(str, level, 3) str
11              from t
12             where length(substr(str, level, 3)) = 3
13            connect by level <= length(str)
14         )
15   where connect_by_isleaf = 1
16   start with rno = 1
17  connect by rno = prior rno + 1;
STR
Dat,ata,tab,aba,bas,ase