The SQL spec defers to XQuery to define what the option flags are
for LIKE_REGEX patterns. XQuery says that:
* 's' allows the dot character to match newlines, which by
default it will not;
* 'm' allows ^ and $ to match at newlines, not only at the
start/end of the whole string.
Thus, these are *not* inverses as they are for the similarly-named
POSIX options, and neither one corresponds to the POSIX 'n' option.
Fortunately, Spencer's library does expose these two behaviors as
separately twiddlable flags, so we just have to fix the mapping from
JSP flag bits to REG flag bits. I also chose to rename the symbol
for 's' to DOTALL, to make it clearer that it's not the inverse
of MLINE.
Also, XQuery says that if the 'q' flag "is used together with the m, s,
or x flag, that flag has no effect". I read this as saying that 'q'
overrides the other flags; whoever wrote our code seems to have read
it backwards.
Lastly, while XQuery's 'x' flag is related to what Spencer's code
does for REG_EXPANDED, it's not the same or a subset. It seems best
to treat XQuery's 'x' as unimplemented for now. Maybe later we can
expand our regex code to offer 'x'-style parsing as a separate option.
While at it, refactor the jsonpath code so that (a) there's only
one copy of the flag transformation logic not two, and (b) the
processing of flags is independent of the order in which the flags
are written.
We need some documentation updates to go with this, but I'll
tackle that separately.
Back-patch to v12 where this code originated.
Discussion: https://postgr.es/m/CAPpHfdvDci4iqNF9fhRkTqhe-5_8HmzeLt56drH%2B_Rv2rNRqfg@mail.gmail.com
Reference: https://www.w3.org/TR/2017/REC-xpath-functions-31-20170321/#flags
75445c1 has caused various failures in tests across the tree after
updating some error messages, so fix the newly-expected output.
Author: Michael Paquier
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/8332.1558048838@sss.pgh.pa.us
This commit contains multiple improvements to error reporting in jsonpath
including but not limited to getting rid of following things:
* definition of error messages in macros,
* errdetail() when valueable information could fit to errmsg(),
* word "singleton" which is not properly explained anywhere,
* line breaks in error messages.
Reported-by: Tom Lane
Discussion: https://postgr.es/m/14890.1555523005%40sss.pgh.pa.us
Author: Alexander Korotkov
Reviewed-by: Tom Lane
Jsonpath now accepts integers with leading zeroes and floats starting with
a dot. However, SQL standard requires to follow JSON specification, which
doesn't allow none of these cases. Our json[b] datatypes also restrict that.
So, restrict it in jsonpath altogether.
Author: Nikita Glukhov
Non-backtracking flex parsers work faster than backtracking ones. So, this
commit gets rid of backtracking in jsonpath_scan.l. That required explicit
handling of some cases as well as manual backtracking for some cases. More
regression tests for numerics are added.
Discussion: https://mail.google.com/mail/u/0?ik=a20b091faa&view=om&permmsgid=msg-f%3A1628425344167939063
Author: John Naylor, Nikita Gluknov, Alexander Korotkov
SQL 2016 standards among other things contains set of SQL/JSON features for
JSON processing inside of relational database. The core of SQL/JSON is JSON
path language, allowing access parts of JSON documents and make computations
over them. This commit implements partial support JSON path language as
separate datatype called "jsonpath". The implementation is partial because
it's lacking datetime support and suppression of numeric errors. Missing
features will be added later by separate commits.
Support of SQL/JSON features requires implementation of separate nodes, and it
will be considered in subsequent patches. This commit includes following
set of plain functions, allowing to execute jsonpath over jsonb values:
* jsonb_path_exists(jsonb, jsonpath[, jsonb, bool]),
* jsonb_path_match(jsonb, jsonpath[, jsonb, bool]),
* jsonb_path_query(jsonb, jsonpath[, jsonb, bool]),
* jsonb_path_query_array(jsonb, jsonpath[, jsonb, bool]).
* jsonb_path_query_first(jsonb, jsonpath[, jsonb, bool]).
This commit also implements "jsonb @? jsonpath" and "jsonb @@ jsonpath", which
are wrappers over jsonpath_exists(jsonb, jsonpath) and jsonpath_predicate(jsonb,
jsonpath) correspondingly. These operators will have an index support
(implemented in subsequent patches).
Catversion bumped, to add new functions and operators.
Code was written by Nikita Glukhov and Teodor Sigaev, revised by me.
Documentation was written by Oleg Bartunov and Liudmila Mantrova. The work
was inspired by Oleg Bartunov.
Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Author: Nikita Glukhov, Teodor Sigaev, Alexander Korotkov, Oleg Bartunov, Liudmila Mantrova
Reviewed-by: Tomas Vondra, Andrew Dunstan, Pavel Stehule, Alexander Korotkov
Tom Lane
Alexander Korotkov
Michael Paquier