'' <> NULL

Hi,

I work with Oracle and to it,
a empty quote concatenation is equal NULL.

ORACLE:
select 1 from dual where '' is null
Result: 1
select 1 from dual where trim(' ') is null
result: 1
insert into tabela values ('')
result: insert a value null in a table

POSTGRE
select 1 where '' i snull
Result: NULL
select 1 where trim(' ') is null
result: NULL
insert into tabela values ('')
result: insere '' in table

We can't change all ours source code
bacause there are very occurrences.

Does anybody here in this forum, and that work
with Oracle already resolve this?

Are there any way to change the PG to equal
'' like NULL?

Cristian