I am gathering something that is essentially am "enrollment date" for users. The "enrollment date" is not stored in the database (for a reason too long to explain here), so I have to deduce it from the data. I then want to reuse this CTE in numerous places throughout another query to gather values such as "total orders 1 year before enrollment" and "total orders 1 year after enrollment".
I haven't gotten this code to run, as it's much more complex in my actual data set (this code is paraphrased from the actual code) and I have a feeling it's not the best way to do this. As you can see, my date conditionals are mostly just placeholders, but I think it should be obvious what I am trying to do.
That said, I think this would mostly work. My question is, is there a better way to do this? Additionally, could I combine the rolling year before and rolling year after into one table somehow? (maybe window functions)? This is part of a much bigger query, so the more consolidation I could do, the better it would seem.
For what it's worth, the subquery to derive the "enrollment date" is also more complex than shown here.
With enroll as (Select
user_id,
MIN(date) as e_date
FROM `orders` o
WHERE (subscribed = True)
group by user_id
)
Select*
from users
left join (select
user_id,
SUM(total_paid)
from orders where date > (select enroll.e_date where user_id = user_id) AND date < (select enroll.e_date where user_id = user_id 365 days)
and order_type = 'special'
group by user_id
) as rolling_year_after on rolling_year_after.user_id = users.user_id
left join (select
user_id,
SUM(total_paid)
from orders where date < (select enroll.e_date where user_id = user_id) and date > (select enroll.e_date where user_id = user_id - 365 days)
and order_type = 'special'
group by user_id
) as rolling_year_before on rolling_year_before.user_id = users.user_id
CodePudding user response:
Maybe something like this, not sure if its more performant, but looks a bit cleaner:
With enroll as (Select
user_id,
MIN(date) as e_date
FROM `orders` o
WHERE (subscribed = True)
group by user_id
)
, rolling_year as (
select
user_id,
SUM(CASE WHEN date between enroll.edate and enroll.edate 365 days then (total_paid) else 0 end) as rolling_year_after,
SUM(CASE WHEN date between enroll.edate - 365 days and enroll.edate then (total_paid) else 0 end) as rolling_year_before
from orders
left join enroll
on order.user_id = enroll.user_id
where order_type = 'special'
group by user_id
)
Select *
from users
left join rolling_year
on users.user_id = rolling_year.user_id