Re: patch: function xmltable

Pavel Stehule <pavel.stehule@gmail.com>

From: Pavel Stehule <pavel.stehule@gmail.com>
To: Craig Ringer <craig@2ndquadrant.com>
Cc: PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Date: 2016-09-12T05:52:55Z
Lists: pgsql-hackers
2016-09-12 6:36 GMT+02:00 Craig Ringer <craig@2ndquadrant.com>:

> On 12 September 2016 at 12:28, Craig Ringer <craig@2ndquadrant.com> wrote:
> >> I'll take a closer read-through shortly.
>
> >DEFAULT
> > isn't a normal literal, it's an xpath expression evaluated at the same
> > time as the rowexpression.
>
> Sorry for the spam, but turns out that's not the case as implemented
> here. The docs you referenced say it should be an xpath expression,
> but the implementation here is of a literal value, and examples
> elsewhere on the Internet show a literal value. Unclear if the
> referenced docs are wrong or what and I don't have anything to test
> with.
>
> Feel free to fix/trim the DEFAULT related changes in above docs patch as
> needed.
>
> Also, tests/docs should probably cover what happens when PATH matches
> more than one element, i.e. produces a list of more than one match.
>

It is there for case, when this is allowed. When you change the  target
type to any non XML type, then a error is raised.

I didn't write a negative test cases until the text of messages will be
final (or checked by native speaker).

Regards

Pavel


>
> --
>  Craig Ringer                   http://www.2ndQuadrant.com/
>  PostgreSQL Development, 24x7 Support, Training & Services
>

Commits

  1. Support XMLTABLE query expression

  2. Create <sect3> in the functions-xml section

  3. Improve handling of "UPDATE ... SET (column_list) = row_constructor".

  4. Add xmlexists function