How to look for words in a CLOB - sql

Question

I have been at this process for a wile and have used INSTR() and have never had any problem with it until
now. a.review is a CLOB and INSTR() has worked in a simple SELECT statement.
DECLARE
lv_hotel NUMBER;
seed_cnt NUMBER;
lv_cat NUMBER;
lv_pol NUMBER;
f NUMBER;
BEGIN
FOR f IN 1..4176
LOOP
SELECT a.IDHotel ,DBMS_LOB.INSTR(a.review, b.seed_words), b.CATEGORYID, SUM(b.Polarity)
INTO lv_hotel, seed_cnt, lv_cat, lv_pol
FROM review a, SEEDWORDS b
GROUP BY a.IDHOTEL, b.CategoryID, DBMS_LOB.INSTR(a.review, b.seed_words), a.review, b.seed_words;
FOR lv_cat IN 1..4
LOOP
INSERT INTO RATINGS (RATING)
VALUES(lv_pol);
END LOOP;
END LOOP;
END;
When I run the above code I get the errors as seen below:
Error report -
ORA-00932: inconsistent datatypes: expected - got CLOB
ORA-06512: at line 11
00932. 00000 - "inconsistent datatypes: expected %s got %s"
*Cause:
*Action:
Is there away around this? Should I use a REGEX function?

Answer 1

DBMS_LOB.INSTR
INSTR Functions
This function returns the matching position of the nth
occurrence of the pattern in the LOB, starting from the offset you
specify.
Update:
I never realized you're doing group by a.review. You cannot use CLOB column in a group by clause. No way around that unless you cast it to varchar2. That logic will need to be reconsidered.