Mario Weilguni <mweilguni@sime.com> writes:
> In Oracle, empty strings and null are basicly the same,
Are you sure about that? It'd be a pretty major failure to comply with
SQL standard semantics, if so.
SQL92 3.1 (Definitions):
null value (null): A special value, or mark, that is used to indicate the absence of any data
value.
SQL92 4.1 (Data types)
A null value is an implementation-dependent special value that is distinct from all non-null values of
theassociated data type. There is effectively only one null value and that value is a member of every SQL
datatype. There is no <literal> for a null value, although the keyword NULL is used in some places to indicate
thata null value is desired.
There is no room there for equating NULL with an empty string. I also
read the last-quoted sentence to specifically forbid treating the
literal '' as NULL.
regards, tom lane