Wygląda na to, że próbujesz to zrobić:
select d.RepName,
count(d.RepName) DoctorReportsCount,
count(h.RepName) HospitalsReportsCount,
d.DateAdded
from doctorreports d
inner join hospitals h
on d.RepName = h.RepName
group by d.RepName, d.DateAdded
edytuj:
select *
from
(
select d.RepName,
count(d.RepName) DoctorReportsCount
, d.dateadded
from doctorreports d
group by d.RepName, d.dateadded
) d
left join
(
select h.RepName,
count(h.RepName) HospitalsReportsCount
, h.dateadded hDateadded
from hospitals h
group by h.RepName, h.dateadded
)h
on d.RepName = h.RepName
zobacz SQL Fiddle z wersją demonstracyjną
edit #2, jeśli chcesz zwrócić dane za brakujące dni, radziłbym utworzyć tabelę zawierającą daty kalendarzowe, wtedy możesz zwrócić dane za brakujące dni. Poniższe powinny zwrócić to, czego szukasz. Pamiętaj, że stworzyłem tabelę kalendarza dla tego zapytania:
select COALESCE(d.drep, '') repname,
COALESCE(d.DCount, 0) DoctorReportsCount,
COALESCE(h.HCount, 0) HospitalsReportsCount,
c.dt Dateadded
from calendar c
left join
(
select repname drep,
count(repname) DCount,
dateadded ddate
from doctorreports
group by repname, dateadded
) d
on c.dt = d.ddate
left join
(
select repname hrep,
count(repname) HCount,
dateadded hdate
from hospitals
group by repname, dateadded
) h
on c.dt = h.hdate
and d.drep = h.hrep
zobacz SQL Fiddle z wersją demonstracyjną
Jeśli nie zależy Ci na innych datach, to tak zrobisz to bez date tabela:
select COALESCE(d.RepName, '') repname,
COALESCE(d.DoctorReportsCount, 0) DoctorReportsCount,
COALESCE(h.HospitalsReportsCount, 0) HospitalsReportsCount,
COALESCE(p.PharmacyReportsCount, 0) PharmacyReportsCount,
d.dateadded Dateadded
from
(
select d.RepName,
count(d.RepName) DoctorReportsCount
, d.dateadded
from doctorreports d
group by d.RepName, d.dateadded
) d
left join
(
select h.RepName,
count(h.RepName) HospitalsReportsCount
, h.dateadded hDateadded
from hospitals h
group by h.RepName, h.dateadded
)h
on d.RepName = h.RepName
and d.dateadded = h.hDateadded
left join
(
select p.RepName,
count(p.RepName) PharmacyReportsCount
, p.dateadded hDateadded
from PharmacyReports p
group by p.RepName, p.dateadded
)p
on d.RepName = p.RepName
and d.dateadded = p.hDateadded
