Parent child and relationship in Oracle

Question

We have a table named test have both parent and child level information. The relationship between these two has been formed at another table called TEST_REL.

Could some body please help to get the Child-Parent with this.

Thanks.

CREATE TABLE TEST
(        CHILD_PAR VARCHAR2(10 BYTE),
        CHILD_PAR_KEY VARCHAR2(10 BYTE)
) ;

Insert into TEST VALUES (CHILD_PAR,CHILD_PAR_KEY) values ('CHILD1','CHILD1KEY');
Insert into TEST values (CHILD_PAR,CHILD_PAR_KEY) values ('CHILD2','CHILD2KEY');
Insert into TEST VALUES (CHILD_PAR,CHILD_PAR_KEY) values ('CHILD3','CHILD3KEY');
Insert into TEST VALUES (CHILD_PAR,CHILD_PAR_KEY) values ('CHILD4','CHILD4KEY');
Insert into TEST VALUES (CHILD_PAR,CHILD_PAR_KEY) values ('PAR1','PAR1KEY');
Insert into TEST VALUES (CHILD_PAR,CHILD_PAR_KEY) values ('PAR2','PAR2KEY');
COMMIT;

CREATE TABLE TEST_REL
 (        CHILDKEY VARCHAR2(10 BYTE),
        PARENT_KEY VARCHAR2(10 BYTE)
 )

Insert into TEST_REL VALUES (CHILDKEY,PARENT_KEY) values ('CHILD1KEY','PAR1KEY');
Insert into TEST_REL VALUES (CHILDKEY,PARENT_KEY) values ('CHILD2KEY','PAR1KEY');
Insert into TEST_REL VALUES (CHILDKEY,PARENT_KEY) values ('CHILD3KEY','PAR2KEY');
Insert into TEST_REL VALUES (CHILDKEY,PARENT_KEY) values ('CHILD4KEY','PAR2KEY');
COMMIT;


Output
CHILD1 PAR1
CHILD2 PAR1
CHILD3 PAR2
CHILD4 PAR2

Answer 1

Not tested but give it a try:

select t1.child_par,t2.child_par
from test t1
    ,test t2
    ,test_rel tr
where tr.childkkey=t1.child_par_key
and   tr.parent_key=t2.child_par_key