Re: Problems with RULE

On 3/6/01, 7:11:48 AM, Jens Hartwig <jens(dot)hartwig(at)t-systems(dot)de> wrote
regarding [SQL] Problems with RULE:

> Hello all,

> I tried to implement the following rule: if someone wants to delete a
record
> from a table t_xyz (id integer, deleted boolean) the record should get a
> delete-flag (deleted = true). When this "pre-deleted" record is deleted
for
> the next time it should be physically deleted from the database.

> I implemented the following rule:

> CREATE RULE r_del_xyz
> AS ON DELETE TO t_xyz WHERE (old.deleted = false)
> DO INSTEAD
> UPDATE t_xyz
> SET deleted = true
> WHERE id = old.id;

> Now I tested the new rule:

> INSERT INTO t_xyz VALUES (1, false);
> INSERT INTO t_xyz VALUES (2, false);
> DELETE FROM t_xyz WHERE id = 1;
> SELECT * FROM t_xyz ;

> id | deleted
> ----+---------
> 2 | f

> What has happened? The rule seems to be ignored and the record was
deleted!

No help I'm afraid, but I encountered something similar the other day on
7.1b3

CREATE RULE ... AS ON UPDATE TO ... WHERE ... DO INSTEAD UPDATE ...

Didn't run, but removing the WHERE did. I had thought someone had raised
this recently, but looking through the list I can't see it now, so maybe
it's a real bug. Is there any mention of this is the CHANGES file in
beta4?

I'll try and check this end whether it applies to all rule-types if you
add a WHERE.

- Richard Huxton