2016-09-16 1:44 GMT+02:00 Craig Ringer <cr...@2ndquadrant.com>: > On 15 September 2016 at 19:31, Pavel Stehule <pavel.steh...@gmail.com> > wrote: > > > b_expr enforces shift/reduce conflict :( > > No problem then. I just thought it'd be worth allowing more if it > worked to do so. > > > I found other opened question - how we can translate empty tag to SQL > value? > > The Oracle should not to solve this question, but PostgreSQL does. Some > > databases returns empty string. > > Oracle doesn't solve the problem? it ERRORs? >
Oracle returns NULL. But there are not any difference between NULL and empty string Regards Pavel > > > I prefer return a empty string - not null in this case. > > I agree, and that's consistent with how most XML is interpreted. XSLT > for example considers <x></x> and <x/> to be pretty much the same > thing. > > > The reason is simple > > - Empty string is some information - and NULL is less information. When > it > > is necessary I can transform empty string to NULL - different direction > is > > not unique. > > Yep, I definitely agree. The only issue is if people want a DEFAULT to > be applied for empty tags. But that's something they can do in a > post-process pass easily enough, since XMLTABLE is callable as a > subquery / WITH expression / etc. > > > -- > Craig Ringer http://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Training & Services >
