On Thu, Mar 7, 2024 at 23:14 Alvaro Herrera <alvhe...@alvh.no-ip.org> wrote:
> On 2024-Mar-07, Tomas Vondra wrote: > > > I was experimenting with the v42 patches, and I think the handling of ON > > EMPTY / ON ERROR clauses may need some improvement. > > Well, the 2023 standard says things like > > <JSON value function> ::= > JSON_VALUE <left paren> > <JSON API common syntax> > [ <JSON returning clause> ] > [ <JSON value empty behavior> ON EMPTY ] > [ <JSON value error behavior> ON ERROR ] > <right paren> > > which implies that if you specify it the other way around, it's a syntax > error. > > > I'm not sure what the SQL standard says about this, but it seems other > > databases don't agree on the order. Is there a particular reason to > > not allow both orderings? > > I vaguely recall that trying to also support the other ordering leads to > having more rules. Yeah, I think that was it. At one point, I removed rules supporting syntax that wasn’t documented. Now maybe we do want that because of compatibility > with other DBMSs, but frankly at this stage I wouldn't bother. +1. >
