Re: [PATCH] Add pretty-printed XML output option

On Fri, Feb 17, 2023 at 1:14 AM Jim Jones <jim(dot)jones(at)uni-muenster(dot)de> wrote:

> After your comment I'm studying the possibility to extend the existing
> xmlserialize function to add the indentation feature. If so, how do you
> think it should look like? An extra parameter? e.g.
>
> SELECT xmlserialize(DOCUMENT '<foo><bar>42</bar></foo>'::XML AS text,
> true);
>
> .. or more or like Oracle does it
>
> SELECT XMLSERIALIZE(DOCUMENT xmltype('<foo><bar>42</bar></foo>') AS BLOB
> INDENT)
> FROM dual;
>

My idea was to follow the SQL standard (part 14, SQL/XML); unfortunately,
there is no free version, but there are drafts at
http://www.wiscorp.com/SQLStandards.html.

<XML character string serialization> ::=
XMLSERIALIZE <left paren> [ <document or content> ]

<XML value expression> AS <data type>
[ <XML serialize bom> ]
[ <XML serialize version> ]
[ <XML declaration option> ]

[ <XML serialize indent> ]
<right paren>

<XML serialize indent> ::=
[ NO ] INDENT

Oracle's extension SIZE=n also seems interesting (including a special case
SIZE=0, which means using new-line characters without spaces for each line).