I thought it would probably give a warning that no available operator for text-text, not this error.
Anyway, thanks!
From: Tom Lane <tgl@sss.pgh.pa.us> Sent: Monday, December 4, 2023 10:15:46 PM To: Ba Jinsheng <bajinsheng@u.nus.edu> Cc: pgsql-bugs@lists.postgresql.org <pgsql-bugs@lists.postgresql.org> Subject: Re: BUG #18222: Unexpected Error--Cannot delete from scalar
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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.
