Remove duplicate values from a listagg in oracle - oracle

Question

I have used listagg to concat and list books along with the supplementary books name.
SELECT DISTINCT SUBSTR(LISTAGG(',-'||B1.BOOK_NO||','||B1.BOOK_NAME||','||A.AUTHOR_NAME||',-'||B2.BOOK_NO||','||B2.BOOK_NAME) WITHIN GROUP (ORDER BY B2.BOOK_NO),2)
FROM BOOK_LIST B1
INNER JOIN AUTHORS A ON A.AUTHOR_NO=B1.AUTHOR_NO
INNER JOIN SUPPLEMENTARY B2 ON B2.BOOK_NO = B1.BOOK_SUP_NO
WHERE B1.SEQ = 123;
But since the number of supplementary books are more i get the main book name repeatedly.
Is there a way to remove the duplicate main book name and number.
My ouput is like this
-99,Anders Carlson ,-109,John Stuart,-99,Anders Carlson ,-47,James Anderson
Here the value 99 is repeated i want only one 99.
Desired Output:
-99,Anders Carlson ,-109,John Stuart,-47,James Anderson
DB data:
Book_list:
NO | MAIN_BOOK_NO | MAIN_BOOK_NAME | BOOK_SUP_NO | AUTHOR_NO
1 | 12 | xyz | 5 | 2
2 | 22 | abc | 7 | 4
Authors:
NO | AUTHOR_NO | AUTHOR_NAME
1 | 2 | Alex
2 | 3 | Leonard
3 | 4 | Benjamin
Supplementary:
NO | BOOK_NO | BOOK_NAME
1 | 5 | ABC
2 | 5 | XYZ
3 | 7 | LMN
4 | 7 | DEF
5 | 7 | NEW
The output should be like
NAME
12,xyz,Alex,-5,ABC,-5,XYZ
22,abc,Benjamin,-7,LMN,-7,DEF,-7,NEW
Similarly for the entire data in the table

Answer 1

If I understand you correctly, you need to append the list of supplementary books to the main book, so you're actually after something like:
SELECT B1.MAIN_BOOK_NO||','||B1.MAIN_BOOK_NAME||',-'||
LISTAGG(B2.BOOK_NO||','||B2.BOOK_NAME, ',-') WITHIN GROUP (ORDER BY B2.BOOK_NO)
FROM BOOK_LIST B1
INNER JOIN AUTHORS A ON A.AUTHOR_NO=B1.AUTHOR_NO
INNER JOIN SUPPLEMENTARY B2 ON B2.BOOK_NO = B1.BOOK_SUP_NO
WHERE B1.SEQ = 123
GROUP BY B1.MAIN_BOOK_NO, B1.MAIN_BOOK_NAME;

Answer 2

See if this works
select T1.MAIN_BOOK_NO, T11.MAIN_BOOK_NAME, LISTAGG(',-'||',-'||T1.BOOK_NO||','||T1.BOOK_NAME) WITHIN GROUP (order by T1.BOOK_NO)
from
(
SELECT B1.MAIN_BOOK_NO, B1.MAIN_BOOK_NAME, B2.BOOK_NO, B2.BOOK_NAME
FROM BOOK_LIST B1
INNER JOIN AUTHORS A ON A.AUTHOR_NO=B1.AUTHOR_NO
INNER JOIN SUPPLEMENTARY B2 ON B2.BOOK_NO = B1.BOOK_SUP_NO
WHERE B1.SEQ = 123
group by B1.MAIN_BOOK_NO, B1.MAIN_BOOK_NAME, B2.BOOK_NO, B2.BOOK_NAME
order by B2.BOOK_NO
) T1
group by T1.MAIN_BOOK_NO, T1.MAIN_BOOK_NAME;