Apply Limit for a Condition - sql

Question

I have a query that returns the credit notes (CN) and debit notes (DN) of an operation, each CN is accompanied by two or more DN (referenced by the field payment_plan_id). At the time of paging, for example I must bring 10 operations, that is 10 CN and their DN, but if I leave the limit at 10, it will also count the debit notes of the transaction that I must return in the query. So, it will only bring me 2, 3 or 4 operations depending on the number of DNs that accompany the credit note.
SELECT
value, installment, payment_plan_id, model,
creation_date, operation
FROM payment_plant
WHERE model != 'IMMEDIATE'
AND operation IN ('CN', 'DN')
AND creation_date BETWEEN '2017-06-12' AND '2017-07-12 23:59:59'
ORDER BY
model,
creation_date,
operation
LIMIT 10
OFFSET 1
Example of the table obviating some fields:
| id | payment_plan_id | value | installment | operation |
---------------------------------------------------------
| 1 | b3cdaede | 12 | 1 | NC |
| 2 | b3cdaede | 3.5 | 1 | ND |
| 3 | b3cdaede | 1.2 | 1 | ND |
| 4 | e1d7f051 | 36 | 1 | NC |
| 5 | e1d7f051 | 5.9 | 1 | ND |
| 6 | 00e6a0b4 | 15 | 1 | NC |
| 7 | 00e6a0b4 | 1 | 1 | ND |
| 8 | 00e6a0b4 | 3.6 | 1 | ND |
How can I limit the Limit so that it only consider the NCs?

Answer 1

Well, the query you give above doesn't do remotely what you describe. Assuming you actually want "the last 10 CN and their DN". You also don't explain what fields CN and DN have in common, so I'm going to assume that the fields are payment_plan_id and installment. Given that here's how you would get it:
WITH last_10_cn AS (
SELECT
value, installment, payment_plan_id, model,
creation_date
FROM payment_plant
WHERE model != 'IMMEDIATE'
AND operation = 'CN'
AND creation_date BETWEEN '2017-06-12' AND '2017-07-12 23:59:59'
ORDER BY
model,
creation_date,
operation
LIMIT 10
OFFSET 1 )
SELECT last_10_cn.*,
dn.value as dn_value, dn.model as dn_model,
dn.creation_date as dn_creation_date
FROM last_10_cn JOIN payment_plant as dn
ON last_10_cn.payment_plan_id = dn.payment_plan_id
AND last_10_cn.installment = dn.installment
ORDER BY
last_10_cn.model,
last_10_cn.creation_date,
last_10_cn.operation
dn.creation_date;
Adjust the above according to the actual join conditions and how you really want things to be sorted.
BTW, your table structure is what's giving you trouble here. DNs should really be a separate table with a foreign key to CNs. I realize that's not how most GLs do it, but the GL model predates relational databases.