Re: [HACKERS] Re: Oracle-compatible lpad/rpad behavior

Jonathan Ellis wrote:
>
> > I went to fix this and then realized I still don't have an adequate spec
> > of how Oracle defines these functions. It would seem logical, for
> > example, that lpad might truncate on the left instead of the right,
> > ie lpad('abcd', 3, 'whatever') might yield 'bcd' not 'abc'. Would
> > someone check?
>
> SQL> select lpad('abcd', 3, 'foobar') from dual;
>
> LPA
> ---
> abc
>
> > Also, what happens if the specified length is less than zero? Error,
> > or is it treated as zero?
>
> SQL> select ':' || lpad('abcd', -1, 'foobar') || ':' from dual;
>
> ':
> --
> ::
>
> (colons added so it's obvious that it's a zero-length string)

AFAIK Oracle is unable to distinguish NULL and zero-length string ;(

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Hannu