This introduces the following SQL/JSON functions for querying JSON
data using jsonpath expressions:
JSON_EXISTS(), which can be used to apply a jsonpath expression to a
JSON value to check if it yields any values.
JSON_QUERY(), which can be used to to apply a jsonpath expression to
a JSON value to get a JSON object, an array, or a string. There are
various options to control whether multi-value result uses array
wrappers and whether the singleton scalar strings are quoted or not.
JSON_VALUE(), which can be used to apply a jsonpath expression to a
JSON value to return a single scalar value, producing an error if it
multiple values are matched.
Both JSON_VALUE() and JSON_QUERY() functions have options for
handling EMPTY and ERROR conditions, which can be used to specify
the behavior when no values are matched and when an error occurs
during jsonpath evaluation, respectively.
Author: Nikita Glukhov <n.gluhov@postgrespro.ru>
Author: Teodor Sigaev <teodor@sigaev.ru>
Author: Oleg Bartunov <obartunov@gmail.com>
Author: Alexander Korotkov <aekorotkov@gmail.com>
Author: Andrew Dunstan <andrew@dunslane.net>
Author: Amit Langote <amitlangote09@gmail.com>
Author: Peter Eisentraut <peter@eisentraut.org>
Author: Jian He <jian.universality@gmail.com>
Reviewers have included (in no particular order):
Andres Freund, Alexander Korotkov, Pavel Stehule, Andrew Alsup,
Erik Rijkers, Zihong Yu, Himanshu Upadhyaya, Daniel Gustafsson,
Justin Pryzby, Álvaro Herrera, Jian He, Anton A. Melnikov,
Nikita Malakhov, Peter Eisentraut, Tomas Vondra
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
Discussion: https://postgr.es/m/20220616233130.rparivafipt6doj3@alap3.anarazel.de
Discussion: https://postgr.es/m/abd9b83b-aa66-f230-3d6d-734817f0995d%40postgresql.org
Discussion: https://postgr.es/m/CA+HiwqHROpf9e644D8BRqYvaAPmgBZVup-xKMDPk-nd4EpgzHw@mail.gmail.com
Discussion: https://postgr.es/m/CA+HiwqE4XTdfb1nW=Ojoy_tQSRhYt-q_kb6i5d4xcKyrLC1Nbg@mail.gmail.com
as determined by include-what-you-use (IWYU)
While IWYU also suggests to *add* a bunch of #include's (which is its
main purpose), this patch does not do that. In some cases, a more
specific #include replaces another less specific one.
Some manual adjustments of the automatic result:
- IWYU currently doesn't know about includes that provide global
variable declarations (like -Wmissing-variable-declarations), so
those includes are being kept manually.
- All includes for port(ability) headers are being kept for now, to
play it safe.
- No changes of catalog/pg_foo.h to catalog/pg_foo_d.h, to keep the
patch from exploding in size.
Note that this patch touches just *.c files, so nothing declared in
header files changes in hidden ways.
As a small example, in src/backend/access/transam/rmgr.c, some IWYU
pragma annotations are added to handle a special case there.
Discussion: https://www.postgresql.org/message-id/flat/af837490-6b2f-46df-ba05-37ea6a6653fc%40eisentraut.org
This commit implements ithe jsonpath .bigint(), .boolean(),
.date(), .decimal([precision [, scale]]), .integer(), .number(),
.string(), .time(), .time_tz(), .timestamp(), and .timestamp_tz()
methods.
.bigint() converts the given JSON string or a numeric value to
the bigint type representation.
.boolean() converts the given JSON string, numeric, or boolean
value to the boolean type representation. In the numeric case, only
integers are allowed. We use the parse_bool() backend function
to convert a string to a bool.
.decimal([precision [, scale]]) converts the given JSON string
or a numeric value to the numeric type representation. If precision
and scale are provided for .decimal(), then it is converted to the
equivalent numeric typmod and applied to the numeric number.
.integer() and .number() convert the given JSON string or a
numeric value to the int4 and numeric type representation.
.string() uses the datatype's output function to convert numeric
and various date/time types to the string representation.
The JSON string representing a valid date/time is converted to the
specific date or time type representation using jsonpath .date(),
.time(), .time_tz(), .timestamp(), .timestamp_tz() methods. The
changes use the infrastructure of the .datetime() method and perform
the datatype conversion as appropriate. Unlike the .datetime()
method, none of these methods accept a format template and use ISO
DateTime format instead. However, except for .date(), the
date/time related methods take an optional precision to adjust the
fractional seconds.
Jeevan Chalke, reviewed by Peter Eisentraut and Andrew Dunstan.
Second attempt at 283a95da92. Since we can't reorder the enum values
of JsonPathItemType, instead reorder the switch cases where they are
used to generally follow the order of the enum values, for better
maintainability.
This reverts commit 283a95da92.
The reordering of JsonPathItemType affects the binary on-disk
compatibility of the jsonpath type, so we must not change it. Revert
for now and consider.
This was failing for queries which try to get the .type() of a
jpiLikeRegex. For example:
select jsonb_path_query('["string", "string"]',
'($[0] like_regex ".{7}").type()');
Reported-by: Alexander Kozhemyakin
Bug: #18035
Discussion: https://postgr.es/m/18035-64af5cdcb5adf2a9@postgresql.org
Backpatch-through: 12, where SQL/JSON path was added.
Run pgindent, pgperltidy, and reformat-dat-files.
This set of diffs is a bit larger than typical. We've updated to
pg_bsd_indent 2.1.2, which properly indents variable declarations that
have multi-line initialization expressions (the continuation lines are
now indented one tab stop). We've also updated to perltidy version
20230309 and changed some of its settings, which reduces its desire to
add whitespace to lines to make assignments etc. line up. Going
forward, that should make for fewer random-seeming changes to existing
code.
Discussion: https://postgr.es/m/20230428092545.qfb3y5wcu4cm75ur@alvherre.pgsql
The reverts the following and makes some associated cleanups:
commit f79b803dc: Common SQL/JSON clauses
commit f4fb45d15: SQL/JSON constructors
commit 5f0adec25: Make STRING an unreserved_keyword.
commit 33a377608: IS JSON predicate
commit 1a36bc9db: SQL/JSON query functions
commit 606948b05: SQL JSON functions
commit 49082c2cc: RETURNING clause for JSON() and JSON_SCALAR()
commit 4e34747c8: JSON_TABLE
commit fadb48b00: PLAN clauses for JSON_TABLE
commit 2ef6f11b0: Reduce running time of jsonb_sqljson test
commit 14d3f24fa: Further improve jsonb_sqljson parallel test
commit a6baa4bad: Documentation for SQL/JSON features
commit b46bcf7a4: Improve readability of SQL/JSON documentation.
commit 112fdb352: Fix finalization for json_objectagg and friends
commit fcdb35c32: Fix transformJsonBehavior
commit 4cd8717af: Improve a couple of sql/json error messages
commit f7a605f63: Small cleanups in SQL/JSON code
commit 9c3d25e17: Fix JSON_OBJECTAGG uniquefying bug
commit a79153b7a: Claim SQL standard compliance for SQL/JSON features
commit a1e7616d6: Rework SQL/JSON documentation
commit 8d9f9634e: Fix errors in copyfuncs/equalfuncs support for JSON node types.
commit 3c633f32b: Only allow returning string types or bytea from json_serialize
commit 67b26703b: expression eval: Fix EEOP_JSON_CONSTRUCTOR and EEOP_JSONEXPR size.
The release notes are also adjusted.
Backpatch to release 15.
Discussion: https://postgr.es/m/40d2c882-bcac-19a9-754d-4299e1d87ac7@postgresql.org
This introduces the SQL/JSON functions for querying JSON data using
jsonpath expressions. The functions are:
JSON_EXISTS()
JSON_QUERY()
JSON_VALUE()
All of these functions only operate on jsonb. The workaround for now is
to cast the argument to jsonb.
JSON_EXISTS() tests if the jsonpath expression applied to the jsonb
value yields any values. JSON_VALUE() must return a single value, and an
error occurs if it tries to return multiple values. JSON_QUERY() must
return a json object or array, and there are various WRAPPER options for
handling scalar or multi-value results. Both these functions have
options for handling EMPTY and ERROR conditions.
Nikita Glukhov
Reviewers have included (in no particular order) Andres Freund, Alexander
Korotkov, Pavel Stehule, Andrew Alsup, Erik Rijkers, Zihong Yu,
Himanshu Upadhyaya, Daniel Gustafsson, Justin Pryzby.
Discussion: https://postgr.es/m/cd0bb935-0158-78a7-08b5-904886deac4b@postgrespro.ru
Per ECMAScript standard (ECMA-262, referenced by SQL standard), the
syntax forms
.1
1.
should be allowed for decimal numeric literals, but the existing
implementation rejected them.
Also, by the same standard, reject trailing junk after numeric
literals.
Note that the ECMAScript standard for numeric literals is in respects
like these slightly different from the JSON standard, which might be
the original cause for this discrepancy.
A change is that this kind of syntax is now rejected:
1.type()
This needs to be written as
(1).type()
This is correct; normal JavaScript also does not accept this syntax.
We also need to fix up the jsonpath output function for this case. We
put parentheses around numeric items if they are followed by another
path item.
Reviewed-by: Nikita Glukhov <n.gluhov@postgrespro.ru>
Discussion: https://www.postgresql.org/message-id/flat/50a828cc-0a00-7791-7883-2ed06dfb2dbb@enterprisedb.com
A number of places were using appendStringInfo() when they could have been
using appendStringInfoString() instead. While there's no functionality
change there, it's just more efficient to use appendStringInfoString()
when no formatting is required. Likewise for some
appendStringInfoString() calls which were just appending a single char.
We can just use appendStringInfoChar() for that.
Additionally, many places were using appendPQExpBuffer() when they could
have used appendPQExpBufferStr(). Change those too.
Patch by Zhijie Hou, but further searching by me found significantly more
places that deserved the same treatment.
Author: Zhijie Hou, David Rowley
Discussion: https://postgr.es/m/cb172cf4361e4c7ba7167429070979d4@G08CNEXMBPEKD05.g08.fujitsu.local
This commit implements jsonpath .datetime() method as it's specified in
SQL/JSON standard. There are no-argument and single-argument versions of
this method. No-argument version selects first of ISO datetime formats
matching input string. Single-argument version accepts template string as
its argument.
Additionally to .datetime() method itself this commit also implements
comparison ability of resulting date and time values. There is some difficulty
because exising jsonb_path_*() functions are immutable, while comparison of
timezoned and non-timezoned types involves current timezone. At first, current
timezone could be changes in session. Moreover, timezones themselves are not
immutable and could be updated. This is why we let existing immutable functions
throw errors on such non-immutable comparison. In the same time this commit
provides jsonb_path_*_tz() functions which are stable and support operations
involving timezones. As new functions are added to the system catalog,
catversion is bumped.
Support of .datetime() method was the only blocker prevents T832 from being
marked as supported. sql_features.txt is updated correspondingly.
Extracted from original patch by Nikita Glukhov, Teodor Sigaev, Oleg Bartunov.
Heavily revised by me. Comments were adjusted by Liudmila Mantrova.
Discussion: https://postgr.es/m/fcc6fc6a-b497-f39a-923d-aa34d0c588e8%402ndQuadrant.com
Discussion: https://postgr.es/m/CAPpHfdsZgYEra_PeCLGNoXOWYx6iU-S3wF8aX0ObQUcZU%2B4XTw%40mail.gmail.com
Author: Alexander Korotkov, Nikita Glukhov, Teodor Sigaev, Oleg Bartunov, Liudmila Mantrova
Reviewed-by: Anastasia Lubennikova, Peter Eisentraut
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
Be more consistent about use of XXXGetDatum macros in new jsonpath
code. This is mostly to avoid having code that looks randomly
different from everyplace else that's doing the exact same thing.
In pg_regress.c, avoid an unreferenced-function warning from
compilers that don't understand pg_attribute_unused(). Putting
the function inside the same #ifdef as its only caller is more
straightforward coding anyway.
In be-secure-openssl.c, avoid use of pg_attribute_unused() on a label.
That's pretty creative, but there's no good reason to suppose that
it's portable, and there's absolutely no need to use goto's here in the
first place. (This wasn't actually causing any buildfarm complaints,
but it's new code in v12 so it has no portability track record.)
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
Amit Langote
Peter Eisentraut
Andrew Dunstan
Bruce Momjian
David Rowley
Tom Lane
Alexander Korotkov
Michael Paquier
Alvaro Herrera