SQL - Joining tables

Question

Hi, im having problems joining all my tables.
Everythings ok, until i add the bold lines in the sql.
code:
SELECT distinct RTRIM(
decode(c.ADDRESS1, NULL, NULL,c.ADDRESS1|| ' , ') ||
decode(c.ADDRESS2, NULL, NULL,c.ADDRESS2|| ' , ') ||
decode(c.ADDRESS3, NULL, NULL,c.ADDRESS3|| ' , ') ||
decode(c.ADDRESS4, NULL, NULL,c.ADDRESS4|| ' , ') ||
decode(c.CITY, NULL, NULL,c.CITY|| ' , ') ||
--decode(c.POSTAL_CODE, NULL, NULL,c.POSTAL_CODE|| ' , ') ||
--c.CITY,' , ') "Address" ,
c.COUNTRY, ' , ') "Address" ,
rtrim(decode(p.person_pre_name_adjunct, null, null, p.person_pre_name_adjunct||' ')||
decode(p.person_first_name, null, null,p.person_first_name||' , ')||
p.person_last_name, ' , ') "Name",
P.PARTY_ID,
p.person_number,
c.contract_number "Subscriber num",
c.item_description,
c.start_date,
c.end_date,
a.customer_class_meaning "Subscriber Type",
n.NOTES "Delivery Point"
from AMS_P_PERSON_V P, xxokb_k_details_v C, AR_CUSTOMERS_V A, AST_NOTES_DETAILS_VL N
WHERE c.PARTY_ID = p.party_id
and p.party_id = a.party_id
and c.party_id = n.source_object_id
and n.NOTE_TYPE_MEANING ='Delivery Instruction'
AND c.contract_status ='ACTIVE'

Answer 1

My guess is that some deliveries don't have delivery instructions, so nothing is retrieved for those rows. In which case an outer join is called for.
The other possibility is that n.source_object_id is not unique so you're getting multiple rows.
But maybe the query crashes your database due to a corrupted block. Who knows?