Oracle: Table aliases in FROM clauses

Using the same alias multiple times

It is possible to use the same alias multiple times in a select statement:

create table tq84_A (id_a number, src char(1), val_a varchar2(5));
create table tq84_B (id_b number, src char(1), val_b varchar2(5));
create table tq84_C (id_c number, src char(1), val_c varchar2(5));

insert into tq84_A values (1, 'A', 'aaa');
insert into tq84_B values (1, 'B', 'bbb');
insert into tq84_C values (1, 'C', 'ccc');

select
   x.val_a,
   x.val_b,
   x.val_c
from
   tq84_A  x                      join
   tq84_B  x  on x.id_a = x.id_b  join
   tq84_C  x  on x.id_a = x.id_c
   ;
--
-- VAL_A VAL_B VAL_C
-- ----- ----- -----
-- aaa   bbb   ccc  

drop table tq84_A;
drop table tq84_B;
drop table tq84_C;