From: Tom Lane <tgl@sss.pgh.pa.us>
To: bajinsheng@u.nus.edu
Cc: pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18222: Unexpected Error--Cannot delete from scalar
Date: Mon, 04 Dec 2023 09:15:46 -0500
Message-ID: <751502.1701699346@sss.pgh.pa.us> (raw)
In-Reply-To: <18222-de86a89e6ed68f3d@postgresql.org>
References: <18222-de86a89e6ed68f3d@postgresql.org>
PG Bug reporting form <noreply@postgresql.org> writes:
> SELECT ('1'-to_hex(2))::BOOLEAN; -- ERROR: cannot delete from scalar
> This error looks strange to me as I do not understand what this error
> means.
Just out of curiosity, what did you expect that to do?
to_hex() produces type text, and there's no "text - text" operator.
What's evidently happening is that the parser finds "jsonb - text"
(i.e., jsonb_delete) as the only potentially applicable operator.
It successfully coerces '1' to a scalar jsonb value, but then
jsonb_delete() spits up because it's expecting an array.
I'm not sure that it was such a great idea to define '-' as having
this meaning for jsonb, but it's been there awhile now so probably
too late to change.
regards, tom lane
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To: pgsql-bugs@postgresql.org
Cc: tgl@sss.pgh.pa.us, bajinsheng@u.nus.edu, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #18222: Unexpected Error--Cannot delete from scalar
In-Reply-To: <751502.1701699346@sss.pgh.pa.us>
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