Need help to format the output of the query.

Question

First of all i would like to say I m newbi in oracle query
and of course thanks to read the thread.
I have a problem formatting a query output.
Actually the query is like the following :
select a1
,b1
,c1
from table
where id.table=1
UNION
select a2
,b2
,c2
from table2
where id.table2=1
order by 1;
exit;
my actual output
a1 b1 c1
a2 b2 c2
a1 b1 c1
a2 b2 c2
my desired output
a1 b1 c1
a2 b2 c2
a1 b1 c1
a2 b2 c2
So what i need is an empy row between the groups of results
and to shift the union query.
thanks in advance

Answer 1

SQL>select * from t1;
        C1         C2         C3
         1          2          3
         2          3          4
         3          4          5
SQL>select * from t2;
        C1         C2         C3
        30         40         50
        20         30         40
        10         20         30
SQL>select c1,c2,c3
  2  from( select c1,c2,c3,1 flg
  3           from t1
  4           union all
  5           select c1,c2,c3,2
  6           from t2
  7           union all
  8           select null,null,null,1
  9           from dual)
10  order by flg,c1,c2,c3 nulls last;
        C1         C2         C3
         1          2          3
         2          3          4
         3          4          5
<br>
        10         20         30
        20         30         40
        30         40         50
7 rows selected.
Funny.......