How to check for duplicates in a 1 to many table - mysql

Question

I have a system which stores peoples outfits. Each outfit contains 1 to many items.
Thus my tables are like this
outfits
+-----------+--------+
| outfit_id | cus_id |
+-----------+--------+
| 1 | 5 |
| 2 | 92 |
+-----------+--------+
items
+---------+-------+-------+
| item_id | name | sku |
+---------+-------+-------+
| 1 | hat | 1111 |
| 2 | pants | 2222 |
| 3 | shirt | 3333 |
| 4 | shoes | 4444 |
+---------+-------+-------+
items_in_outfit
+--------+-----------+---------+
| ino_id | outfit_id | item_id |
+--------+-----------+---------+
| 1 | 1 | 3 |
| 2 | 1 | 2 |
| 3 | 1 | 4 |
| 4 | 2 | 1 |
| 4 | 2 | 3 |
+--------+-----------+---------+
I am given this information:
cus_id=92 wants to create another outfit with the sku's 1111 and 3333
However, this is a duplicate of outfit_id=2. So I want mysql to return me the outfit_id of 2. If its not a duplicate, return nothing. It only counts as a duplicate if the same cus_id is trying to make an outfit which has the exact same sku's already.
If cus_id=5 wants to create another outfit with the sku's 1111 and 3333. It should return nothing (as its not a duplicate) because cus_id=5 doesn't have an outfit with just 1111 and 3333
SELECT o.outfit_id FROM
outfits o JOIN
items_in_outfit iio
ON o.outfit_id = iio.outfit_id JOIN
items i
ON iio.item_id = i.item_id
WHERE cus_id = 92 AND ...

Answer 1

This may help you achieve what you are looking for :
select
cus_id
from(
select
cus_id,
group_concat(sku order by sku asc) as items
from outfits o
join items_in_outfit iio on o.outfit_id = iio.outfit_id
join items i on iio.item_id = i.item_id
group by cus_id
) T
where items = '1111,3333'
SEE DEMO HERE
EDIT : As an outfit can't contain more than 1 instance of the same item, this solution may be better for you as you don't have to order the sku id in your php before :
select
o.outfit_id
from
outfits o
join items_in_outfit iio on o.outfit_id = iio.outfit_id
join items i on iio.item_id = i.item_id
where sku IN (1111, 3333)
group by o.outfit_id having COUNT(*) = 2
SEE SECOND DEMO HERE