创建视图（减去不同表上的两个不同列）

Question

Can I create another view? subtract from total_deposit - total_loan_amount

CREATE VIEW v_total_deposit (total_deposit) as 
select sum(deposit_amount) 
from deposit;

CREATE VIEW v_total_loan (total_loan) as 
SELECT SUM(loan_amount) 
from loan;

Answer 1

@moonir01 MINUS is a set operator, not arithmetic one. You have to subtract two numbers:

CREATE VIEW balance
AS
   SELECT NVL((SELECT TOTAL_DEPOSIT FROM V_TOTAL_DEPOSIT),0) - NVL((SELECT TOTAL_LOAN FROM V_TOTAL_LOAN),0) AS balance
     FROM DUAL 

but you really don't need these views.