SQL query too big - Can I merge this? - sql

Question

I have the query below which seems to work, but it really feels like I should be able to do it in a simpler manner. Basically I have an orders table and a production_work table. I want to find all orders which are not complete, meaning either there's no entry for the order in the production_work table, or there are entries and the sum of the work equals what the order calls for.
SELECT q.* FROM (
SELECT o.ident, c."name" AS cname, s."name" as sname, o.number, o.created, o.due, o.name, o.ud, o.dp, o.swrv, o.sh, o.jmsw, o.sw, o.prrv, o.mhsw, o.bmsw, o.mp, o.pr, o.st
FROM orders o
INNER JOIN stations s on s.ident = o.station_id
INNER JOIN clients c ON s.client_id = c.ident
INNER JOIN (
SELECT p.order_id, SUM(p.ud) AS ud, SUM(p.dp) AS dp, SUM(p.swrv) AS swrv, SUM(p.sh) AS sh, SUM(p.jmsw) AS jmsw, SUM(p.sw) AS sw, SUM(p.prrv) AS prrv,
SUM(p.mhsw) AS mhsw, SUM(p.bmsw) AS bmsw, SUM(p.mp) AS mp, SUM(p.pr) AS pr, SUM(p.st) AS st
FROM production_work p
GROUP BY p.order_id
) pw ON o.ident = pw.order_id
WHERE o.ud <> pw.ud OR o.dp <> pw.dp OR o.swrv <> pw.swrv OR o.sh <> pw.sh OR o.jmsw <> pw.jmsw OR o.sw <> pw.sw OR o.prrv <> pw.prrv OR
o.mhsw <> pw.mhsw OR o.bmsw <> pw.bmsw OR o.mp <> pw.mp OR o.pr <> pw.pr OR o.st <> pw.st
UNION
SELECT o.ident, c."name" AS cname, s."name" as sname, o.number, o.created, o.due, o.name, o.ud, o.dp, o.swrv, o.sh, o.jmsw, o.sw, o.prrv, o.mhsw, o.bmsw, o.mp, o.pr, o.st
FROM orders o
INNER JOIN stations s on s.ident = o.station_id
INNER JOIN clients c ON s.client_id = c.ident
WHERE NOT EXISTS (
SELECT 1 FROM production_work p WHERE p.ident = o.ident
)
) q ORDER BY due DESC

Answer 1

Here's the query I ended up with:
WITH work_totals AS (
SELECT p.order_id, SUM(p.ud + p.dp + p.swrv + p.sh + p.jmsw + p.sw + p.prrv + p.mhsw + p.bmsw + p.mp + p.pr + p.st) AS total
FROM production_work p
GROUP BY p.order_id
), order_totals AS (
SELECT ident, SUM(ud + dp + swrv + sh + jmsw + sw + prrv + mhsw + bmsw + mp + pr + st) AS total
FROM orders
GROUP BY ident
)
SELECT o.ident, c."name" AS cname, s."name" as sname, o.number, o.created, o.due, o.name, o.ud, o.dp, o.swrv, o.sh, o.jmsw, o.sw, o.prrv, o.mhsw, o.bmsw, o.mp, o.pr, o.st
FROM orders o
INNER JOIN stations s on s.ident = o.station_id
INNER JOIN clients c ON s.client_id = c.ident
INNER JOIN order_totals ot ON o.ident = ot.ident
LEFT OUTER JOIN work_totals w ON o.ident = w.order_id
WHERE w.order_id IS NULL OR ot.total <> w.total

Answer 2

The two queries in your UNION are almost identical so you can merge them into a single query as follows. I just changed the JOIN to the pw subquery to be a OUTER LEFT JOIN - which has the same reslut as your union because I incldued an additional OR clause in the WHERE statement to return these orders that dont have a record in the pw sub-query.
SELECT o.ident, c."name" AS cname, s."name" as sname, o.number, o.created, o.due, o.name, o.ud, o.dp, o.swrv, o.sh, o.jmsw, o.sw, o.prrv, o.mhsw, o.bmsw, o.mp, o.pr, o.st
FROM orders o
INNER JOIN stations s on s.ident = o.station_id
INNER JOIN clients c ON s.client_id = c.ident
LEFT OUTER JOIN (
SELECT p.order_id, SUM(p.ud) AS ud, SUM(p.dp) AS dp, SUM(p.swrv) AS swrv, SUM(p.sh) AS sh, SUM(p.jmsw) AS jmsw, SUM(p.sw) AS sw, SUM(p.prrv) AS prrv,
SUM(p.mhsw) AS mhsw, SUM(p.bmsw) AS bmsw, SUM(p.mp) AS mp, SUM(p.pr) AS pr, SUM(p.st) AS st
FROM production_work p
GROUP BY p.order_id
) pw ON o.ident = pw.order_id
WHERE (o.ud <> pw.ud OR o.dp <> pw.dp OR o.swrv <> pw.swrv OR o.sh <> pw.sh OR o.jmsw <> pw.jmsw OR o.sw <> pw.sw OR o.prrv <> pw.prrv OR
o.mhsw <> pw.mhsw OR o.bmsw <> pw.bmsw OR o.mp <> pw.mp OR o.pr <> pw.pr OR o.st <> pw.st
)
OR pw.order_id IS NULL
ORDER BY due DESC

Answer 3

Queries of this form: Show rows which do not have a match in the other table.
Can be done like this:
select <columns>
from <table1>
left outer join <table2> on <join_condition>
where table2.column IS NULL
This will find rows from table1 which do not have anything in table2 matching the join condition.
For your summing query, I would do something like this...
select table1.order_number, total = sum(table2.order_amount)
from table1
left outer join table2 on table1.order_number = table2.order_number
group by order_number
having total < (some_number) OR total is null
That combines getting orders which have no matches, and getting orders with less than some total order_amount.