A simple problem with natural join

Question

i have 2 tables what have columns with distinct's names are referenced.
natural join not works 'cose only foreign key reference this 2 tables.
Have something to make table join in using an specific foreign key??
I'm using oracle9i
Example:
table a( a_cod number, a_name varchar2(20))
table b( b_cod number, b_month_year date, b_salary number)
ALTER TABLE b ADD ( CONSTRAINT b_a_FK FOREIGN KEY (b_cod)
REFERENCES a (a_cod));
select * from a natural join b
where trunc(b_month_year) = trunc(sysdate)

Answer 1

I'm not express me correctly.
We have 2 tables like this:
CREATE TABLE PPTBA001
  PPA001_GROUP             NUMBER(3)            NOT NULL,
  PPA001_PEOPLECODE        VARCHAR2(20 BYTE)    NOT NULL,
  PPA001_NAME              VARCHAR2(60 BYTE)    NOT NULL,
  PPA001_DATEOFBIRTHDAY    DATE                 NOT NULL);
CREATE TABLE CLTBA001
  CLA001_GROUP            NUMBER(3)             NOT NULL,
  CLA001_CLIENTCODE       VARCHAR2(20 BYTE)     NOT NULL,
  CLA001_SITUATION        NUMBER(1)             DEFAULT 1);
SELECT * FROM PPTBA001 NATURAL JOIN CLTBA001;
ALTER TABLE CLTBA001 ADD (
  CONSTRAINT CLA001_PPAA001_FK1 FOREIGN KEY (CLA001_GROUP, CLA001_CLIENTCODE)
    REFERENCES PPTBA001 (OFA001_GROUP,OFA001_PEOPLECODE));
      the select returns without results. 'cose does not have columns like same name.
Natural join use a columns with same name. I need something use an foreign key.
Why?? Now i have a problem .. i need aggregate one more column in primary key
and i need change all selects that have join with PPTBA001 and put manualy a new column.. if have a other possibility like natural join to using a foreign key to join the selects problems is so more easy to resolve.
Message was edited by:
jonas.lima