Re: [PG9.1] CTE usage - Mailing list pgsql-general

From Adrian Klaver
Subject Re: [PG9.1] CTE usage
Date
Msg-id 52371FC1.6090003@gmail.com
Whole thread Raw
In response to Re: [PG9.1] CTE usage  (Ladislav Lenart <lenartlad@volny.cz>)
Responses Re: [PG9.1] CTE usage  (Ladislav Lenart <lenartlad@volny.cz>)
List pgsql-general
On 09/16/2013 07:38 AM, Ladislav Lenart wrote:
> On 16.9.2013 15:50, Adrian Klaver wrote:
>> On 09/16/2013 04:57 AM, Ladislav Lenart wrote:
>>> On 16.9.2013 13:26, Alban Hertroys wrote:
>>

>> .."
>
>
> Hello.
>
> Thank you but I have read this in the official documentation before posting my
> (previous) reply. So to quote the important bit about CASCADE:
>
>      Delete any rows referencing the deleted row
>
> My example defines the table item with FK to the table item_type1 and FK to the
> table item_type2. Specifying anything on these two constraints does not help one
> bit when I delete an item, because item_type1 nor item_type2 does not reference
> any... Therefore I suspect that Alban Hertroys had a different model in mind where:
>   * item would not have any FKs,
>   * item_type1 would have FK to item,
>   * item_type2 would have FK to item?
>
> I just wasn't sure, hence I have asked him for a more detailed answer. However,
> I am pretty sure ON DELETE CASCADE would not help in my current setup.


I guess the question is whether you actually have set up FK
relationships between items.item_type1_id, items.item_type2_id and the
respective ids in item_type1 and item_type2?

In other words do you have REFERENCE item_type1 ... on item_type1_id?

If so and you add the ON DELETE CASCADE, you could DELETE from
item_type1 and it would delete the respective items rows.

>
> Ladislav Lenart
>
>
>


--
Adrian Klaver
adrian.klaver@gmail.com


pgsql-general by date:

Previous
From: Merlin Moncure
Date:
Subject: Re: Best way to populate nested composite type from JSON`
Next
From: Ladislav Lenart
Date:
Subject: Re: [PG9.1] CTE usage