Postgres 14

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create table schedules (id int, staff int, subgroupId int, status int)

CREATE TABLE

create table schedulegroup(groupid int, subgroup int,  created date)

CREATE TABLE

insert into schedules values(1, 1, 1, 1)

INSERT 0 1

insert into schedules values(2, 2, 2, 2)

INSERT 0 1

insert into schedules values(3, 2, 2, 3)

INSERT 0 1

insert into schedules values(4, 2, 3, 2)

INSERT 0 1

insert into schedulegroup values(15, 1, '2022-06-12')

INSERT 0 1

insert into schedulegroup values(15, 2, '2022-06-11')

INSERT 0 1

insert into schedulegroup values(15, 3, '2022-06-11')

INSERT 0 1

SELECT count(distinct case when sc.status in (1, 2) then sc.staff end),
       count(distinct case when sc.status in (1, 2) then sc.subgroupId end),
       count(sc.id)
FROM schedules sc
WHERE EXISTS (SELECT *
              FROM schedulegroup sg
              WHERE sg.groupid = 15
              AND sc.subgroupId = sg.subgroup 
              AND sg.created BETWEEN '2022-06-01' AND '2022-06-12')

count
count
count

2
3
4

SELECT 1