On Tue, 2 Aug 2005, Jeff Davis wrote:
> >>Does the SQL standard provide no way to have a NULL character in a
> >>string constant? Is single-quote the only special character?
> >
> > I don't think it forbids you from using the null character. It's not like
> > the strings are zero terminated. Some encodings might not allow the null
> > character, but that's different.
>
> But doesn't PostgreSQL forbid us from using the NULL character in a
> query at all? Don't we always have to escape or encode it in some way?
Pg does not allow \0 in strings at all. Try SELECT 'abc\0def'; in the
current version of pg.
The sql standard doesn't forbid null values in strings as far as I know
and that's all I talked about. To have a sql standard string with null
inside you just insert the 0 byte (for normal single byte encodings), no
escaping needed.
Internally pg handles strings as \0-terminated entities which is a bit
unfortunate but that's what we have. That's why 'abc\0def' became the
string 'abc'. Most character sets forbid \0 in strings anyway.
--
/Dennis Björklund