From: Tom Lane <tgl@sss.pgh.pa.us>
To: Leo Volin <lvolin@intelligentaudit.com>
cc: "pgsql-bugs@lists.postgresql.org" <pgsql-bugs@lists.postgresql.org>
Subject: Re: Case clause doesn't report syntactic error
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Comments: In-reply-to Leo Volin <lvolin@intelligentaudit.com>
	message dated "Sat, 14 Sep 2024 21:27:35 -0000"
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Date: Sat, 14 Sep 2024 18:33:54 -0400
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Leo Volin <lvolin@intelligentaudit.com> writes:
> This generates no error:
> select case '4'::int when 1 then 1 when 4 then 11 else 2 end;
> (prints 11)
> It doesn't match the documented format:
> CASE WHEN condition THEN result
>      [WHEN ...]
>      [ELSE result]
> END

You need to read down a couple of paragraphs to where the
"simple" variant of CASE is explained [1]:

CASE expression
    WHEN value THEN result
    [WHEN ...]
    [ELSE result]
END

Perhaps we should rearrange that page so both syntax variants
appear at the top; but it's not wrong.

			regards, tom lane

[1] https://www.postgresql.org/docs/current/functions-conditional.html#FUN=
CTIONS-CASE