SQL - How to find entries where a value is missing between two rows - sql

Question

We are using Presto SQL at my job. I have spent hours trying to search for the answer to this question but can't find an answer and it's quite difficult to search for. Solving this issue opens the door to fixing a lot of problems.
I need to write a query that tries to find all entries where REQUEST_CANCEL & CHARGED exist but CANCEL_ACCOUNT is missing.
CHARGED & CANCEL_ACCOUNT should always come after REQUEST_CANCEL.
Table Name: CUSTOMER_INFO
|DATE_TIME|CUST_ID |ACTION |
|20180726 |1234 |CHARGED |
|20180726 |1234 |CANCEL_ACCOUNT|
|20180726 |1234 |REQUEST_CANCEL|
All these values exist in the same table. Here's what I have so far.
SELECT *
FROM
(SELECT *
FROM CUSTOMER_INFO
WHERE
DATE_TIME = 20180726
AND ACTION = REQUEST_CANCEL) as a
JOIN
(SELECT *
FROM CUSTOMER_INFO
WHERE
DATE_TIME = 20180726
AND ACTION = CHARGED) as b
ON a.CUST_ID = b.CUST_ID
WHERE
a.TIME < b.TIME
Let me explain it in a way that makes sense.
A = REQUEST_CANCEL
B = CANCEL_ACCOUNT
C = CHARGED
How do you query for when A and C exist but B is missing. The sequence needs to be exact A > B > C. It's essentially querying for something that doesn't exist between two values that do exist. In my current query, B can be returned between the two values and that's NOT what I want.

Answer 1

I think you're searching for NOT EXISTS and a corellated subquery.
SELECT *
FROM (SELECT *
FROM customer_info
WHERE action = 'REQUEST_CANCEL') rc
INNER JOIN (SELECT *
FROM customer_info
WHERE action = 'CHARGED') c
ON c.cust_id = rc.cust_id
AND c.date_time >= rc.date_time
WHERE NOT EXISTS (SELECT *
FROM customer_info ca
WHERE ca.cust_id = rc.cust_id
AND ca.action = 'CANCEL_ACCOUNT'
AND ca.date_time >= rc.date_time
AND ca.date_time <= c.date_time);

Answer 2

Use group by and having:
select cust_id
from customer_info ci
where date_time = 20180726 and
action in ('REQUEST_CANCEL', 'CHARGED', 'CANCEL_ACCOUNT')
group by cust_id
having sum(case when action = 'REQUEST_CANCEL' then 1 else 0 end) > 0 and
sum(case when action = 'CHARGED' then 1 else 0 end) > 0 and
sum(case when action = 'CANCEL_ACCOUNT' then 1 else 0 end) = 0 ;
Each sum() counts the number of matching records for the customer with that action. The > 0 says that one exists. The = 0 says that none exist.
The database doesn't matter for this logic. Here is a SQL Fiddle using MySQL.