Re: Is this correct behavior for ON DELETE rule?

"Rick Schumeyer" <rschumeyer@ieee.org> writes:
> -- delete to item and book instead of bookview
> create rule bookviewdel as on delete to bookview do instead (
>       delete from book where id=old.id;
>       delete from item where id=old.id;
> );

This is an ancient gotcha: as soon as you delete the book row, there is
no longer any such entry in the bookview view ... and "old.id" is
effectively a reference to the bookview view, so the second delete
finds no matching rows.

If you can reasonably turn the view into a LEFT JOIN in one direction or
the other, then a workaround is to delete from the nullable side first.

            regards, tom lane