SQL Server subsets, Sql Server

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--Sql Server 2014 Express Edition
--Batches are separated by 'go'

create table AllTab
(
plate_id int,
prod_id int, 
location int
)

insert into AllTab
values
(100,10,    1),
(100,10,    2),
(100,10,    3),
(100,10,    4),

(100,20,    1),
(100,20,    2),
(100,20,    3),
(100,20,    4),
(100,20,    5),
(100,20,    6),
(100,20,    9),

(100,30,    1),
(100,30,    2),
(100,30,    9),

(100,40,    1),
(100,40,    2),
(100,40,    12),
(100,40,    14),

(100,40,    1),
(100,40,    2),
(100,40,    25),
(100,40,    30),

(200,10,    1),
(200,10,    2),
(200,10,    3),
(200,10,    4),

(200,20,    1),
(200,20,    2),
(200,20,    3),
(200,20,    4),
(200,20,    5),
(200,20,    6),
(200,20,    7),

(200,30,    3),
(200,30,    4),
(200,30,    9),

(300,10,    1),
(300,10,    2),
(300,10,    3),
(300,10,    5),

(300,20,    1),
(300,20,    2),
(300,20,    3),
(300,20,    4),
(300,20,    5),
(300,20,    6),
(300,20,    7),
(300,20,    9),

(300,30,    1),
(300,30,    2),
(300,30,    5)

select plate_id, location
from alltab a
group by plate_id, location
having count(distinct prod_id) = (select count(distinct prod_id) from alltab a2 where a2.plate_id = a.plate_id);

View schema
Execution time: 0,03 sec, rows selected: 7, rows affected: 51, absolute service time: 0,19 sec