[mysql] 뷰의 SELECT는 FROM 절에 하위 쿼리를 포함합니다.

두 개의 테이블이 있고 뷰를 만들어야합니다. 테이블은 다음과 같습니다.

credit_orders(id, client_id, number_of_credits, payment_status)
credit_usage(id, client_id, credits_used, date)

이를 위해 다음 쿼리를 사용합니다. “create view”부분이없는 쿼리는 잘 작동하지만 “create view”를 사용하면 “View의 SELECT에 FROM 절에 하위 쿼리가 포함되어 있습니다.”오류가 표시됩니다. 문제 및 가능한 해결책은 무엇입니까?

create view view_credit_status as
(select credit_orders.client_id,
        sum(credit_orders.number_of_credits) as purchased,
        ifnull(t1.credits_used,0) as used
 from credit_orders
 left outer join (select * from (select credit_usage.client_id,
                                        sum(credits_used) as credits_used
                                 from credit_usage
                                 group by credit_usage.client_id) as t0
                  ) as t1 on t1.client_id = credit_orders.client_id
 where credit_orders.payment_status='Paid'
 group by credit_orders.client_id)

답변

create view view_clients_credit_usage as
    select client_id, sum(credits_used) as credits_used
    from credit_usage
    group by client_id

create view view_credit_status as
    select
        credit_orders.client_id,
        sum(credit_orders.number_of_credits) as purchased,
        ifnull(t1.credits_used,0) as used
    from credit_orders
    left outer join view_clients_credit_usage as t1 on t1.client_id = credit_orders.client_id
    where credit_orders.payment_status='Paid'
    group by credit_orders.client_id)