SQL From the same table find records shared by common criteria

DB: postgres (PostgreSQL) 10.16 (Ubuntu 10.16-0ubuntu0.18.04.1)

I have a table device_clients in which following data is present:

id	device_id	client_id
1	1	1
2	2	1
3	3	1
4	4	1
5	5	1
6	6	1
7	7	1
8	8	1
9	1	2
10	1	3
11	1	4
12	2	2
13	2	3
14	2	4
15	3	2
16	3	3
17	3	4

I need to find out devices common between each client I provide. For e.g. following are the devices for each client

Client-1 => 1, 2, 3, 4, 5, 6, 7, 8
Client-2 => 1, 2, 3
Client-3 => 1, 2, 3
Client-4 => 1, 2, 3

So for clients 1, 2, 3 the common devices expected are 1, 2, 3.

Can anybody please help me formulate an efficient query to achieve the desired results?

Answer

You can use aggregation. For instance:

select device_id
from t
where client_id in (1, 2, 3)
group by device_id
having count(*) = 3;

For convenience, you can pass the list of clients in as an array, allowing you to use:

select device_id
from t
where client_id = any(:client_ar)
group by device_id
having count(*) = cardinality(:client_ar)