Query joing Four tables

Question

Hi,
I've four tables as below:
SQL> desc per_absence_attendances
Name                                      Null?    Type
ABSENCE_ATTENDANCE_ID                     NOT NULL NUMBER(10)
BUSINESS_GROUP_ID                         NOT NULL NUMBER(15)
ABSENCE_ATTENDANCE_TYPE_ID                NOT NULL NUMBER(9)
ABS_ATTENDANCE_REASON_ID                           NUMBER(9)
PERSON_ID                                 NOT NULL NUMBER(10)
AUTHORISING_PERSON_ID                              NUMBER(10)
REPLACEMENT_PERSON_ID                              NUMBER(10)
PERIOD_OF_INCAPACITY_ID                            NUMBER(9)
ABSENCE_DAYS                                       NUMBER(9,4)
SQL> desc per_absence_attendance_types
Name                                      Null?    Type
ABSENCE_ATTENDANCE_TYPE_ID                NOT NULL NUMBER(9)
BUSINESS_GROUP_ID                                  NUMBER(15)
INPUT_VALUE_ID                                     NUMBER(9)
DATE_EFFECTIVE                            NOT NULL DATE
NAME                                      NOT NULL VARCHAR2(30)
ABSENCE_CATEGORY                                   VARCHAR2(30)
SQL> desc per_all_people_f
Name                                      Null?    Type
PERSON_ID                                 NOT NULL NUMBER(10)
EFFECTIVE_START_DATE                      NOT NULL DATE
EFFECTIVE_END_DATE                        NOT NULL DATE
BUSINESS_GROUP_ID                         NOT NULL NUMBER(15)
PERSON_TYPE_ID                            NOT NULL NUMBER(15)
FULL_NAME                                          VARCHAR2(240)
SQL> desc Per_all_assignments_f
Name                                      Null?    Type
ASSIGNMENT_ID                             NOT NULL NUMBER(10)
PERSON_ID                                 NOT NULL NUMBER(10)
SUPERVISOR_ASSIGNMENT_ID                           NUMBER(15)The tables are related as below:
i). per_all_people_f contains information about employee, like person_id, full names
ii). per_absence_attendances contains information for leave records for employees. This table is joined to per_all_people_f using the column PERSON_ID
iii). per_absence_attendance_types contains information about types of absences (e.g Annual Leave). Joined to per_absence_attendances on column ABSENCE_ATTENDANCE_TYPE_ID
iv). Per_all_assignments_f contains information about employee assignment (supervisor etc). Is joined to per_all_people_f using the column PERSON_ID. The coulmn SUPERVISOR_ASSIGNMENT_ID contains the person_id for the supervisor of this employee.
I would like to use SUPERVISOR_ASSIGNMENT_ID to get the Full name of the supervisor for this employee. Ultimately, I'm looking for an output like this:
FULL_NAME  ABSENCE_TYPE  ABSENCE_DAYS APPROVED_BY
XXXXX         Annual Leave       5                         yyyyWhere yyyy is the full name for the supervisor of employee xxxx. Anyone with a hint on this?
Regards
dula
Edited by: user13005731 on Jul 1, 2012 10:27 PM

Answer 1

may be
select p.full_name, supervisor.full_name as supervisor_full_name
  from per_all_people_f             p,
       per_absence_attendances      aa,
       per_absence_attendance_types t,
       per_all_assignments_f        a,
       per_all_people_f             supervisor
where p.person_id = aa.person_id(+)
   and aa.absence_attendance_type_id = t.absence_attendance_type_id(+)
   and p.person_id = a.person_id
   and sysdate between p.effective_start_date and p.effective_end_date
   and supervisor.person_id = a.supervisor_assignment_id