Re: [GENERAL] Cascading Updates

I have tried to do it using _rules_, but completed by my own code in the
library realising my data model. The _rule_ is appropriate place to do
it, but they are not realised properly and can't be used in serious
applications yet.


On Fri, 29 Jan 1999, Marcus Mascari wrote:

> Date: Fri, 29 Jan 1999 01:04:58 -0800 (PST)
> From: Marcus Mascari <mascarim@yahoo.com>
> To: pgsql-general@postgreSQL.org
> Subject: [GENERAL] Cascading Updates
>
> Hello.
>
> I was wondering if it is possible, using the current
> refint.c code, to perform CASCADING UPDATES.  It
> appears that the trigger will fire on either an
> update or a delete and call check_foreign_key() to
> perform deletes ('cascade') or updates with NULL's
> ('setnull'), but not updates with the new key.
>
> Am I missing something, or should you be able to
> have the following:
>
> CREATE TABLE employees (
> employee varchar(10) not null
> );
>
> CREATE TABLE payroll (
> employee varchar(10) not null,
> salaray double not null
> );
>
> INSERT INTO employees VALUES ('mascarim');
> INSERT INTO payroll VALUES ('mascarim','1250000');
>
> and a trigger which, when the employee id
> is updated:
>
> UPDATE employees SET employee = 'mmascari' WHERE
> employee = 'mascarim';
>
> in the employees table, cascades to
> update the employee id in the payroll table.
>
> Is this currently not possible?  It appears that
> the result is that an update to the employees
> table, will yield a DELETE in the payroll table
> instead of an update.
>
> Any hints would be greatly appreciated.
>
> Thanks,
>
> Marcus Mascari (mascarim@yahoo.com)
>
>
>
>
>
>
>
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