Sum a UNION query

Question

URGENT PLS!!
hi,
pls im trying to query my database but i dont know how to write the query. here is what i was told to do.
there are 3 tables,
1. HCP table that hold all the name of hospitals (primary key is HCP_ID)
2. EMPLOYEE table, which hold the info about employee (primary key is EMP_ID and foreign key is HCP_ID)
3.DEPENDANT table which hold info about the families(dependants) of an EMPLOYEE (primary key is DEP_ID, foreign key is EMP_ID)
now my boss wants a report on the hospitals(HCP) that have 1-499 number of lives.(lives, i mean employee and dependant) which should include the name of the hospital and the count of lives in each hospital as the only 2 colunm. thanks
Edited by: tiana on Jul 11, 2011 3:17 AM

Answer 1

Something like this;
select h.HCP_Name as Hospital_Name
      ,e.cn       as Number_of_Lives
from   HCP h
      ,(select  e.hcp_id
               ,count(1) over (partition by e.hcp_id) cn
        from    Employees e
               ,Dependant d
        where   e.Emp_ID = d.Emp_ID) e
where  e.cn > 0 and e.cn < 500
and    h.hcp_id = e.hcp_id
/Edited by: bluefrog on Jul 11, 2011 11:42 AM