2016-09-27 5:53 GMT+02:00 Craig Ringer <cr...@2ndquadrant.com>: > On 24 September 2016 at 14:01, Pavel Stehule <pavel.steh...@gmail.com> > wrote: > > >> Did some docs copy-editing and integrated some examples. Explained how > >> nested elements work, that multiple top level elements is an error, > >> etc. Explained the time-of-evaluation stuff. Pointed out that you can > >> refer to prior output columns in PATH and DEFAULT, since that's weird > >> and unusual compared to normal SQL. Documented handling of multiple > >> node matches, including the surprising results of somepath/text() on > >> <somepath>x<!--blah-->y</somepath>. Documented handling of nested > >> elements. Documented that xmltable works only on XML documents, not > >> fragments/forests. > > > > > > I don't understand to this sentence: "It is possible for a PATH > expression > > to reference output columns that appear before it in the column-list, so > > paths may be dynamically constructed based on other parts of the XML > > document:" > > This was based on a misunderstanding of something you said earlier. I > thought the idea was to allow this to work: > > SELECT * FROM xmltable('/x' PASSING > '<x><elemName>a</elemName><a>value</a></x>' COLUMNS elemName text, > extractedValue text PATH elemName); > > ... but it doesn't: > > > SELECT * FROM xmltable('/x' PASSING > '<x><elemName>a</elemName><a>value</a></x>' COLUMNS elemName text, > extractedValue text PATH elemName); > ERROR: column "elemname" does not exist > LINE 1: ...' COLUMNS elemName text, extractedValue text PATH elemName); > > ... so please delete that text. I thought I'd tested it but the state > of my tests dir says I just got distracted by another task at the > wrong time. >
deleted Regards Pavel > > -- > Craig Ringer http://www.2ndQuadrant.com/ > PostgreSQL Development, 24x7 Support, Training & Services >
xmltable-11.patch.gz
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