How to join two Oracle Query ?

Yes , I want to join the these query using join.

You cannot do the join using UNION since the columns do not match. What exactly do you want to do? And what about the table defs, maybe with some test data?

I'm trying to join two tables like this...

select
part.prod_full_descr,
part.part_id,
part.prod_full_descr,
c.part_id,
c.parent_part_id,
prepart.prod_full_descr ,
cont.contact_function ,
cont.contact_name
FROM
Part_T part ,
component_t c ,
part_t prepart ,
contact_t cont ,
part_t cont_part ,
part_t pre_cont_part
WHERE
 part.part_id = c.parent_part_id (+)
AND part.fiscal_quarter = c.fiscal_quarter (+)
AND prepart.fiscal_quarter = '2014-2'
AND prepart.part_id = c.part_id
AND part.part_id = cont.part_id (+)
AND part.fiscal_quarter = '2014-2'
and part.part_nbr = '12224'

This above query returning more that 500 rows. but its not correct.

Please post sample data and expected results.  I'm not following what you mean by 'join'.

Forget my last post...  I think I see it.

Give me a little time.

Agreed ;-)
In order to solve (or at least to understand) your problem, we need:
- table definitions (create table ....)
- expected results (as mentioned by slightwv)
- some test data would be nice

Sorry slightwv, but this statement will fail to execute: e.g. see table alias 'pub' or 'prod' (where are their corresponding tables)...
Nevertheless this SQL is quite confusing whether we have the table defs w/o data or not. I don't see a clear and structured statement here at all (e.g. where is the "base table" / start?). We/I use to build SQLs upon this pattern (which makes a lot of things a lot easier, even for the Optimizer):

select col1,
       col2,
       col3
  from table_3 c,
       table_2 b,
       table_1 a
 where a.prime_key = 'whatever'
   and b.fk_on_a = a.prime_key
   and c.fk_on_b = b.prime_key;

Select allOpen in new window

Maybe you should consider to redesign your statement in order to get a clear view on the purpose ;-)

>>Sorry slightwv, but this statement will fail to execute: e.g. see table alias 'pub' or 'prod' (where are their corresponding tables)...

I used the askers first attempt as the starting point and just merged the other SQL into it.

I guess I missed some table names and aliases.  Hopefully the asker can get the idea of where I was going and correct the table names.