Re: BUG #15826: BUG: Where-Clause referring to iso-8859-1 column in CTEis ignored in Update-statement

On Fri, May 31, 2019 at 11:55 AM PG Bug reporting form <noreply@postgresql.org> wrote:

The following bug has been logged on the website:

Bug reference:      15826
Logged by:          Thomas Hantel
Email address:      tom.hantel@googlemail.com
PostgreSQL version: 11.3
Operating system:   Fedora Linux
Description:       

We are currently seeing the following unexpected effect:

In one of our services there is a statement that first sets up a CTE to
filter the data and then an UPDATE-statement that refers to that data. If
the WHERE-clause in the update refers to a column that is not selected in
the CTE, the whole clause is ignored so that all of the rows in the table
get updated.
[..]
We would expect an error to be thrown in all cases where undefined columns
are referenced.

This is not a bug. It may seem weird but it is expected behaviour under scope resolution.

The cte does not have an id column but dummy has, so it is used.