ORA-20000

Another way to split comma separated values to columns.

with t_string as
(
 select 'John,Roy,Alice,Helen,Mark,Barbara,Elizabeth,Lara' as str
 from   dual
)
select regexp_substr(t_string.str,'[^,]+', 1, level)
from   t_string
connect by level <= regexp_count(t_string.str,'[^,]+')

Other methods:

Результат Select'а в виде одной строки и одна строка в виде набора строк