Customize SPLIT Function written in Oracle (PLSQL)

A common task when selecting data from a database is to take a set of values a query returns and format it as a comma delimited list. Another task that's almost as common is the need to do the reverse take a comma delimited list of values in a single string and use it as a table of values.

To serve this purpose I preferred following function to Split string.

Split Function:

create or replace function split(
  p_InputString   varchar2,
  p_Position      number,
  p_Delimiter     varchar2
  )
return varchar2
is
   v_list varchar2(32767) := p_Delimiter || p_InputString;
   v_start_position number;
   v_end_position number;
begin
   v_start_position := instr(v_list, p_Delimiter, 1, p_Position);
   if v_start_position > 0 then
      v_end_position := instr( v_list, p_Delimiter, 1, p_Position + 1);
         if v_end_position = 0 then
            v_end_position := length(v_list) + 1;
         end if;
         return(substr(v_list, v_start_position + 1, v_end_position - v_start_position - 1));
   else
         return NULL;
   end if;
end split;
/
Show Error

Output 1:

select split('Tamim Khan',1,' ') from dual;
SPLIT('TAMIMKHAN',1,'')                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
-----------------------------------------
Tamim

Output 2:

select split('Tamim Khan',2,' ') from dual;

SPLIT('TAMIMKHAN',1,'')                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
------------------------------------------
Khan

Output 3:

select split('Dhanmondi,Dhaka',1,',') from dual;                        
SPLIT('TAMIMKHAN',1,'')                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
----------------------------------------------
Dhanmondi

Output 4:

select split('Dhanmondi,Dhaka',2,',') from dual;                        
SPLIT('TAMIMKHAN',1,'')                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
----------------------------------------------
Dhaka