Merge Query Question

Question

Ok, I have a Table TEST_ACCOUNTS that has all new customer information of new applicants for credit cards. Because of a Bank rules, customers are not assigned
a customer_id number right away, takes about a month, so in this table I will have some CUST_SKEYS that are [0] and some that have account numbers.
I pick off all the [0] from this Table above and find out which ones got an account and those go into a Table LATEST_SKEYS but not all of them will update, so
there will still be some [0]'s.
Anyways, so now I would like to MERGE the accounts that were found back to the master Table, which is TEST_ACCOUNTS using the query below, the query does
work, but all cust_skeys that used to be 0 were turned to null, and I would prefer for them to stay 0. I know that I can use NVL and NVL2 to turn a null value to whatever I want,
but I only have experience using that when I select columns form existing tables, am not sure how to do this with a MERGE, something that I want to learn more about.
It isn't really creating a headache for me, but I would like to keep things consistent and keep the 0, 0's and not NULL.
Another columns that rides along with the row information is app_num, which is a unique number that is assigned to an application for a credit card so I am doing the matching
on that and then I update the cust_skeys.
Hopefully this makes sense. Help appreciated.
MERGE INTO TEST_ACCOUNTS t1
USING (Select * from LATEST_SKEYS) t2
ON (t1.application_num = t2.application_num)
WHEN MATCHED THEN UPDATE
SET t1.cust_skey = t2.customer_skey;

Answer 1

user621335 wrote:
... the query does
work, but all cust_skeys that used to be 0 were turned to null, and I would prefer for them to stay 0.
MERGE INTO TEST_ACCOUNTS t1
USING (Select * from LATEST_SKEYS) t2
ON (t1.application_num = t2.application_num)
WHEN MATCHED THEN UPDATE
SET t1.cust_skey = t2.customer_skey;You probably want to limit the records returned by t2 to just those whose customer_skey values are not null:
MERGE INTO TEST_ACCOUNTS t1
USING (Select * from LATEST_SKEYS where customer_skey is not null) t2
ON (t1.application_num = t2.application_num)
WHEN MATCHED THEN UPDATE
SET t1.cust_skey = t2.customer_skey;