CREATE TABLE customer (cust_id CLOB, cust_name CLOB, acc_type CLOB, acc_bal NUMBER, no_of_loans NUMBER, credit_score NUMBER, branch_id NUMBER, state CLOB)
CREATE TABLE bank (branch_id NUMBER, bname CLOB, no_of_customers NUMBER, city CLOB, state CLOB)
CREATE TABLE loan (loan_id CLOB, loan_type CLOB, cust_id CLOB, branch_id CLOB, amount NUMBER)

Find the average credit score of the customers who do not have any loan.
SELECT AVG(credit_score) FROM customer WHERE NOT cust_id IN (SELECT cust_id FROM loan)
SELECT AVG("credit_score") FROM "customer" WHERE NOT "cust_id" IN (SELECT "cust_id" FROM "loan")