Search Postgresql Archives

Re: DELETE trigger, direct or indirect?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, Feb 16, 2023 at 6:51 PM Adrian Klaver <adrian.klaver@xxxxxxxxxxx> wrote:
You have two tables with list in their name, so are rows deleted from
both. Just to be clear enity_list should actually be entity_list?

Also how are entity and enity_list related?

I have to confess that your questions surprise me a bit.
I thought the model was pretty clear from the SQL.
We have two entities, Foo (my entity table), and another Bar (my entity_list table),
with Bar reference 0 or more Foos, recording which ones it references in an association table.

Are the values for the name field in entity and enity(entity)_list the
same for a given entity?

The name of Foo and Bar are completely independent.
 
> transfering the old entity name to it thanks to an UPDATE on
> entity_name, thus preserving the old name.

How?
Again how would you determine where the action started?

Deleting a Foo cascades to the _member assoc-table.
If the cascade is SET NULL, then I can have an UPDATE TRIGGER on _member.
I no longer care where the action started.
 
> Then an INSERT trigger on entity could locate any (indexed) "stashed"
> entity names in that extra non-FK column in entity_list_member,

How would it locate it if  the name that defined the FK(entity(name)) was NULL?

In the extra non-FK column I mentioned explicitly, in the _member assoc-table.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]

  Powered by Linux