I wrote a function to break a string into parts delimitted by $ Now I need to access it with select from but getting error - string

Question

I have created following function to split a given string delimited by $.
I want to call the function as part of SQL query and get the result as rows.
CREATE OR REPLACE FUNCTION string_tokenize2
( p_string IN CLOB
-- p_delim in varchar2
)
RETURN SYS_REFCURSOR
AS
cur1 SYS_REFCURSOR;
BEGIN
OPEN cur1 FOR
SELECT regexp_substr(p_string
,'[^$]+'
,1
,LEVEL) AS str
FROM sys.dual
CONNECT BY LEVEL <= regexp_count(p_string
,'\$') + 1;
RETURN cur1;
END string_tokenize2;
/
However when I tried it using in a SQL resulted in following error.
Kindly assist me how to proceed here ,

Answer 1

select string_tokenize2('')from dual;
put your IN variable in the ( )

Answer 2

Do you have any constraint to stick to the function as it is ? OR
Why not create an object type and change the function to return a table type and then use it in SQL ?
--create the type
CREATE OR REPLACE TYPE string_tokenize2_obj IS TABLE OF VARCHAR2(4000);
--Function changes
CREATE OR REPLACE FUNCTION string_tokenize2(p_string IN CLOB)
RETURN string_tokenize2_obj AS
l_tab string_tokenize2_obj;
BEGIN
SELECT to_char(str)
BULK COLLECT
INTO l_tab
FROM (SELECT regexp_substr(p_string
,'[^$]+'
,1
,LEVEL) str
FROM dual
CONNECT BY LEVEL <= regexp_count(p_string
,'\$') + 1);
RETURN l_tab;
END string_tokenize2;
/
SQL> SELECT column_value str FROM TABLE(string_tokenize2('abc$def$geh$ijkl'));
STR
--------------------------------------------------------------------------------
abc
def
geh
ijkl
SQL>

Answer 3

You can either
1) use xmltable and xmltype to read data from sys_refcursor functions results if you need that data in select statement:
ie you can use the same your function without any changes, but read it using xmltable+xmltype:
select *
from xmltable(
'/ROWSET/ROW'
passing xmltype(string_tokenize2('1$2$3$4'))
columns
str varchar2(100) path 'STR'
);
Results:
STR
---------------------------------------
1
2
3
4
2) or use plsql implicit results if you are just need to get data from any client: https://oracle-base.com/articles/12c/implicit-statement-results-12cr1
Example:
CREATE OR REPLACE PROCEDURE string_tokenize2
( p_string IN CLOB
-- p_delim in varchar2
)
AS
cur1 SYS_REFCURSOR;
BEGIN
OPEN cur1 FOR
SELECT regexp_substr(p_string
,'[^$]+'
,1
,LEVEL) AS str
FROM sys.dual
CONNECT BY LEVEL <= regexp_count(p_string
,'\$') + 1;
DBMS_SQL.RETURN_RESULT(cur1);
END string_tokenize2;
/
begin
string_tokenize2('1,2,3,4');
end;
Result:
SQL> exec string_tokenize2('1,2,3,4');
ResultSet #1
STR
---------------------------------------
1,2,3,4
3) or just return sys_refcursor to client app as a bind variable for fetching:
begin
:res := string_tokenize2('1,2,3,4');
end;
Example in sql*plus:
SQL> var res refcursor
SQL> exec :res := string_tokenize2('1$2$3$4');
SQL> print res
STR
--------------------
1
2
3
4
4) Or varchar2 collections/varrays as suggested by other users