We can split a string into substrings using PL/SQL built in functions SUBSTR(), INSTR() and LENGTH() together.

Follwing code snippets helps you in splitting a string into substrings.

Snippet to split string into pieces:::

CREATE OR REPLACE FUNCTION func_str_split(str_to_split IN OUT VARCHAR2
,str_delimiter IN VARCHAR2) RETURN VARCHAR2
IS
t_pos NUMBER;
t_len NUMBER;
t_strlen NUMBER;
t_strresult VARCHAR2(2000);
BEGIN
t_strresult := NULL;
IF str_to_split IS NOT NULL THEN
t_len := LENGTH(str_delimiter);
t_strlen := LENGTH(str_to_split);
t_pos := INSTR(str_to_split,str_delimiter);
IF t_pos > 0 THEN
t_strresult := SUBSTR(str_to_split,1,t_pos-1);
str_to_split := SUBSTR(str_to_split,t_pos+t_len,t_strlen);
ELSE
t_strresult := str_to_split;
str_to_split := NULL;
END IF;
END IF;
RETURN t_strresult;
END func_str_split;

Use following procedure to call above function:::

CREATE OR REPLACE PROCEDURE proc_str_split(str_to_split IN OUT VARCHAR2
,str_delimiter IN VARCHAR2)
IS
declare

END proc_str_split;