Re: DELETE trigger, direct or indirect? - Mailing list pgsql-general

From Adrian Klaver
Subject Re: DELETE trigger, direct or indirect?
Date
Msg-id be552356-ca68-7ce6-bafe-50a82450952c@aklaver.com
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In response to Re: DELETE trigger, direct or indirect?  ("David G. Johnston" <david.g.johnston@gmail.com>)
Responses Re: DELETE trigger, direct or indirect?
List pgsql-general
On 2/16/23 08:55, David G. Johnston wrote:
> On Thu, Feb 16, 2023 at 9:46 AM Adrian Klaver <adrian.klaver@aklaver.com 
> <mailto:adrian.klaver@aklaver.com>> wrote:
> 
>     On 2/16/23 05:23, Dominique Devienne wrote:
>      > Hi. This is a bit unusual. We have a foreign key between two tables,
>      > with ON DELETE CASCADE, to preserve referential integrity. But we
>      > apparently also need to preserve the severed reference (by
>     natural key,
>      > i.e. its name), to later on reconnect the two entities
>     after-the-fact,
>      > should the parent row re-appear later on (in the same transaction
>     or not
>      > it still unclear).
> 
>     This is going to need a more detailed description of the relationship
>     between the two tables:
> 
>     1) The actual FK relationship.
> 
>     2) What "...preserve the severed reference (by natural key,  i.e. its
>     name)" means?
> 
>     3) What information will be used to reconnect the child rows to the
>     parent rows?
> 
> 
> Maybe the OP should be using ON DELETE SET NULL instead of CASCADE?

That is where I am headed, however it will need more information to 
determine whether that makes sense or not.

> 
> David J.

-- 
Adrian Klaver
adrian.klaver@aklaver.com




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