Convert comma separated string to array in PL/SQL

Question

How do I convert a comma separated string to a array?

I have the input \'1,2,3\' , and I need to convert it into an array.

Answer 1

declare
seprator varchar2(1):=',';
dosweeklist varchar2(4000):='a,b,c';
begin
for i in (SELECT  SUBSTR(dosweeklist,
                         case when level=1 then 1 else INSTR(dosweeklist,seprator,1,LEVEL-1)+1 end,
                         NVL(NULLIF(INSTR(dosweeklist,seprator,1,LEVEL),0),length(dosweeklist)+1) - case when level=1 then 1 else INSTR(dosweeklist,seprator,1,LEVEL-1)+1 end) dat 
          FROM dual
          CONNECT BY LEVEL <= LENGTH(dosweeklist) - LENGTH(REPLACE(dosweeklist,seprator,'')) +1)
loop
dbms_output.put_line(i.dat);
end loop;
end;
/

so select query only in for loop can do the trick, by replacing dosweeklist as your delimited string and seprator as your delimited character.

Lets see output

a

b

c

Answer 2

We can never run out of alternatives of doing the same thing differently, right? I recently found this is pretty handy:

DECLARE
   BAR   VARCHAR2 (200) := '1,2,3';
BEGIN
   FOR FOO IN (    SELECT REGEXP_SUBSTR (BAR,
                                         '[^,]+',
                                         1,
                                         LEVEL)
                             TXT
                     FROM DUAL
               CONNECT BY REGEXP_SUBSTR (BAR,
                                         '[^,]+',
                                         1,
                                         LEVEL)
                             IS NOT NULL)
   LOOP
      DBMS_OUTPUT.PUT_LINE (FOO.TXT);
   END LOOP;
END;

Outputs:

1
2
3