Using SQL recursive query as AND statement - sql

Question

I have the following flowchart. Hopefully, it's self-explanatory
On top of the hierarchy there's a request that is a basic parent of all the request below it. Requests below have the 'id', 'parent_id', 'state' fields
My final goal is to find all parents ids that satisfy all AND statements including the last one (hierarchical query). However, I don't know how to use it as an AND statement.
The hierarchical query looks like this:
with cte
as (select id, state
from tbl_request as rH
WHERE id = /* each id from the very first select */
UNION ALL
select rH.id, rH.state
from tbl_request as rH
join cte
on rH.parent_id = cte.id
and (cte.state is null or cte.state NOT IN('not-legit'))
)
select case when exists(select 1 from cte where cte.state IN('not-legit'))
then 1 else 0 end
Expectantly, it does what it's supposed to
The solution was suggested in the question
Return true/false in recursive SQL query based on condition
For your convenience, here's a SQL Fiddle

Answer 1

I think I've worked out what you want.
You need to recurse through all the nodes and their children, returning its state and its ultimate root parent_id.
Then aggregate by that ID and exclude any group that contains a row with state = 'not-legit'. In other words, flip the logic to a double negative.
WITH cte AS (
SELECT rH.id, rH.state, rH.id AS top_parent
FROM tbl_request as rH
WHERE (rH.state is null or rH.state <> 'not-legit')
AND rH.parent_id IS NULL
UNION ALL
SELECT rH.id, rH.state, cte.top_parent
FROM tbl_request as rH
JOIN cte
ON rH.parent_id = cte.id
)
SELECT top_parent
FROM cte
GROUP BY
cte.top_parent
HAVING COUNT(CASE WHEN cte.state = 'not-legit' THEN 1 END) = 0;
You could also change the logic back to a positive, but it would need to look like this:
HAVING COUNT(CASE WHEN cte.state is null or cte.state <> 'not-legit' THEN 1 END) = COUNT(*)
In other words, there are the same number of these filtered rows as there are all rows.
This feels more complex than what I have put above.
SQL Fiddle

Answer 2

Replace your
WHERE id = /* each id from the very first select */
by
WHERE id in (
SELECT r.id FROM tbl_request AS r
/* there's also an INNER JOIN (hopefully, it won't be an obstacle) */
WHERE r.parent_id is null
/* a lot of AND statements */
)
Also, you should use UNION instead of UNION ALL, since there is no point using duplicated tuples (id and state) in this case.
To summarize, your query should look like this one
with cte
as (select id, state
from tbl_request as rH
WHERE id in (
SELECT r.id
FROM tbl_request AS r
/* there's also an INNER JOIN (hopefully, it won't be an obstacle) */
WHERE r.parent_id is null
/* a lot of AND statements */
) UNION
select rH.id, rH.state
from tbl_request as rH
join cte
on rH.parent_id = cte.id
and (cte.state is null or cte.state NOT IN('not-legit'))
)
Your subquery can contain any inner joins or any number of AND operators you need, as long as it returns one column (select r.id) it will work fine.