From: Tom Lane <tgl@sss.pgh.pa.us>
To: shahar@cybear.co
cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #17660: JSONPATH issue using like_regex followed by the &&
 operator
In-reply-to: <17660-3fe48447b080d5b6@postgresql.org>
References: <17660-3fe48447b080d5b6@postgresql.org>
Comments: In-reply-to PG Bug reporting form <noreply@postgresql.org>
	message dated "Sat, 22 Oct 2022 11:55:24 -0000"
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-ID: <3367659.1666446526.1@sss.pgh.pa.us>
Date: Sat, 22 Oct 2022 09:48:46 -0400
Message-ID: <3367660.1666446526@sss.pgh.pa.us>
Archived-At: 
 <https://www.postgresql.org/message-id/3367660.1666446526%40sss.pgh.pa.us>
Precedence: bulk

PG Bug reporting form <noreply@postgresql.org> writes:
> I've found an issue with the like_regex statement when using it together
> with another && condition.
> In the following example I'm expecting the result will end as:
> [{"id":9,"value":"a"}] but instead, it ends with an empty array:

> WITH a(attributes) AS (
> 	SELECT '[{"id":9,"value":"a"},{"id":9,"value":"a$"}]'::jsonb
> )
> SELECT jsonb_path_query_array(attributes,'$[*] ? (!(@.id==9 && @.value
> like_regex "\$$"))') FROM a

I think you're short a backslash:

=# WITH a(attributes) AS (
SELECT '[{"id":9,"value":"a"},{"id":9,"value":"a$"}]'::jsonb
)
SELECT jsonb_path_query_array(attributes,'$[*] ? (!(@.id==9 && @.value
like_regex "\\$$"))') FROM a
;
  jsonb_path_query_array   
---------------------------
 [{"id": 9, "value": "a"}]
(1 row)

I believe one level of backslashing gets eaten by the jsonpath parser
while parsing the literal, so your version ends as LIKE "$$" which
is not different from LIKE "$" and will match every string.

			regards, tom lane