Solved

how to use group by in mulity table query?

Posted on 2004-08-31
7
1,598 Views
Last Modified: 2012-05-05
I have two table that named table_user and table_area,
in table_user there some user records:
=========================
username,areacode,sex
=========================
azsd,0376,1
fake,0377,0
chome,0376,1
user3,0376,1
=========================

in table_area stores areacodes and their areaname
=========================
areacode,areaname
=========================
0376,xinyang
0377,nanyang
=========================

I want to make an query return back records like that:
=========================
username,areaname,sex
=========================
azsd,xinyang,1
fake,nanyang,0
chome,xinyang,1
user3,xinyang,1
=========================

which format sql phras that I would use?
I use that text and sql anlays can't pass though grammar check:
select "table_user".username, "table_area".areaname,"table_user".sex from "table_user","table_area","table_user" group by "table_user".areacode;
sure i don't think it can work.
the help files with oracle 9i have only few graphic,no more info....

thanks you read this question post by a poorman poor in english
0
Comment
Question by:azsd
  • 3
  • 3
7 Comments
 
LVL 9

Expert Comment

by:pratikroy
ID: 11939827
You have a simple requirement :

Select a.username, b.areaname, a.sex
From  table_user a, table_area b
Where a.areacode = b.areacode;

Hope this helps!
0
 

Author Comment

by:azsd
ID: 11939916
yes it works,
unluckly the where statements occured an little things in my envorenment:
i have an user record

userx,0378,1

it will discarded and only 4 rows selected....
I want have these results

azsd,xinyang,1
fake,nanyang,0
chome,xinyang,1
user3,xinyang,1
userx,0378,1

how can i redirect the areacode that no exists in table_area as areaname?
0
 

Author Comment

by:azsd
ID: 11939976
I have this idea:

Select a.username, b.areaname, a.sex
From  table_user a, table_area b
Where a.areacode = b.areacode
union
select username,areacode as areaname,sex
from table_user
where areacode not in (select areacode from table_area);

but i think "not in (select)" will be slowest in oracle commands
0
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 4

Accepted Solution

by:
mottor earned 150 total points
ID: 11939992
Select a.username, nvl(b.areaname,a.areacode), a.sex
From  table_user a, table_area b
Where a.areacode = b.areacode(+);
0
 
LVL 9

Assisted Solution

by:pratikroy
pratikroy earned 150 total points
ID: 11940027
SQL> select * from table_user;

USERNAME                       AREACODE          SEX
------------------------------ ---------- ----------
azsd                           0376                1
fake                           0377                0
chome                          0376                1
user3                          0376                1
userx                          0378                1

SQL> select * from table_area;

AREACODE   AREANAME
---------- ------------------------------
0376       xinyang
0377       nanyang

SQL> select a.USERNAME, NVL(b.areaname, a.areacode), a.sex
  2  from table_user a, table_area b
  3  where a.areacode = b.areacode(+)
  4  /

USERNAME                       NVL(B.AREANAME,A.AREACODE)            SEX
------------------------------ ------------------------------ ----------
azsd                           xinyang                                 1
chome                          xinyang                                 1
user3                          xinyang                                 1
fake                           nanyang                                 0
userx                          0378                                    1

SQL>

Hope this helps !
0
 

Author Comment

by:azsd
ID: 11940070
thanks pratikroy and mottor,
tested fine in my server~~
0
 
LVL 9

Expert Comment

by:pratikroy
ID: 11940170
You are welcome azsd. Glad I could be of some help to you !
0

Featured Post

Secure Your Active Directory - April 20, 2017

Active Directory plays a critical role in your company’s IT infrastructure and keeping it secure in today’s hacker-infested world is a must.
Microsoft published 300+ pages of guidance, but who has the time, money, and resources to implement? Register now to find an easier way.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
ORA-04071: missing BEFORE, AFTER or INSTEAD OF keyword 2 93
SQL query for highest sequence 4 59
Oracle cursor lifecycle inside procedure. 2 24
Oracle Nested table uses ? 2 44
Why doesn't the Oracle optimizer use my index? Querying too much data Most Oracle developers know that an index is useful when you can use it to restrict your result set to a small number of the total rows in a table. So, the obvious side…
Truncate is a DDL Command where as Delete is a DML Command. Both will delete data from table, but what is the difference between these below statements truncate table <table_name> ?? delete from <table_name> ?? The first command cannot be …
This video shows how to copy a database user from one database to another user DBMS_METADATA.  It also shows how to copy a user's permissions and discusses password hash differences between Oracle 10g and 11g.
This video shows how to set up a shell script to accept a positional parameter when called, pass that to a SQL script, accept the output from the statement back and then manipulate it in the Shell.

685 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question