MySql select from already selected data - mysql

Question

Hello I am trying to select data from the already selected values.
Current query:
select t.ticket_num, t.item_id, t.trans_id
from tickets as t
inner join ticket_items as ti
on ti.id = t.item_id
where ti.online = 1
and ti.bundle = 5
and ti.type_id = 2
Data sample:
num | item | tran
5699 1328 766
5700 1328 766
5701 1328 766
5702 1328 766
5703 1328 766
5704 1330 767
5705 1330 767
5706 1330 767
5707 1330 767
5708 1330 767
5709 1332 768
5710 1332 768
5711 1332 768
5712 1332 768
5713 1332 768
5714 1333 768
5715 1333 768
5716 1333 768
5717 1333 768
5718 1333 768
5719 1334 768
5720 1334 768
5721 1334 768
5722 1334 768
5723 1334 768
5724 1336 769
5725 1336 769
5726 1336 769
5727 1336 769
5728 1336 769
5729 1338 770
5730 1338 770
5731 1338 770
5732 1338 770
5733 1338 770
5734 1339 770
5735 1339 770
5736 1339 770
5737 1339 770
5738 1339 770
5739 1340 770
5740 1340 770
5741 1340 770
5742 1340 770
From this data I want only the ones that have 15 or more items on tran, as you can see 766 has only 5 but 768 has 15 so I want everything from this data that has more than or equal to 15.
Thanks

Answer 1

Perform a subquery that looks up all groups of tran in your desired query that have 15 or more records (the key is using the GROUP BY and HAVING clauses). Then in your main query select all records where tran is found IN the subquery. So for instance:
select
t.ticket_num, t.item_id, t.trans_id
from tickets as t
inner join ticket_items as ti
on ti.id = t.item_id
where ti.online = 1
and ti.bundle = 5
and ti.type_id = 2
and trans_id in
(select t.trans_id
from tickets as t
inner join ticket_items as ti
on ti.id = t.item_id
where ti.online = 1
and ti.bundle = 5
and ti.type_id = 2
GROUP BY t.trans_id
HAVING count(t.trans_id)>=15
)
You could probably clean up the redundant JOIN by pulling it out into a Common Table Expression like so:
WITH tquery as (SELECT *
from tickets
inner join ticket_items as ti
on ti.id = t.item_id
where ti.online = 1
and ti.bundle = 5
and ti.type_id = 2
)
select
ticket_num, item_id, trans_id
from tquery
where trans_id in
(select t.trans_id
from tquery as t
GROUP BY t.trans_id
HAVING count(t.trans_id)>=15
)
More about the having clause in case you're wondering how it works: What's the difference between HAVING and WHERE?