View's SELECT contains a subquery in the FROM clause
I have two tables and I need to create a view. The tables are:
credit_orders(id, client_id, number_of_credits, payment_status)
credit_usage(id, client_id, credits_used, date)
I use the following query to do this. The query without the "create view" part works well but with "create view", it shows the error "View's SELECT contains a subquery in the FROM clause". What could be the issue & possible solution:
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)
Solution 1:
As per documentation:
MySQL Docs
- The SELECT statement cannot contain a subquery in the FROM clause.
Your workaround would be to create a view for each of your subqueries.
Then access those views from within your view view_credit_status
Solution 2:
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)