Select data from 4 or more tables

Question

Hi All,
I got stUck up in a problem in Oracle.
I have 4 tables say t1,t2,t3,t4
t1 has c1 is a primary key,c2,c3
t2 has c1 is a foreign key ,c4,c5
t3 has c1 is a foreign key,c6,c7
t4 has c1 is a foreign key,c8,c9
I want to retreive the data from all these tables at a time.i.e. c1,c2,c3,c4,c5,c6,c7,c8,c9 such that
it doesnot result in duplicacy od records.
that is the record should be grouped if it has same value
FOR EXAMPLE
a query
"select company.company_name,import_from,export_to from company,importfrom,exportto
where company.company_name=exportto.company_name
and
company.company_name=importfrom.company_name"
will retreive
COMPANY_NAME iMPORT_FROM EXPORT_TO
IMG CANADA INDIA
IMG CANADA ITALY
IMG CANADA BRAZIL
IMG CANADA CHINA
IMG CANADA SOUTH AFRICA
IMG MEXICO INDIA
IMG MEXICO ITALY
IMG MEXICO BRAZIL
IMG MEXICO CHINA
IMG MEXICO SOUTH AFRICA
AND I WANT
COMPANY_NAME iMPORT_FROM EXPORT_TO
IMG null INDIA
IMG null ITALY
IMG NULL BRAZIL
IMG NULL CHINA
IMG NULL SOUTH AFRICA
IMG CANADA NULL
IMG MEXICO NULL
PLEASE REPLY SOON
Manoj

Answer 1

Try this query.
select c.company_name, e.exp, null
from company c, export_to e
where c.company_name = e.company_name
union
select c.company_name, null, i.imp
from company c, import_from i
where c.company_name = i.company_name
If you have 4 tables, you'll need 3 queries with union statement.