From: Daryl Richter <daryl@brandywine.com>
To: pgsql-sql@postgresql.org
Subject: Re: Updating cidr column with network operator
Date: Thu, 22 Sep 2005 16:26:01 -0400
Message-ID: <43331359.1020703@brandywine.com> (raw)
In-Reply-To: <72c14f47f1dca0ae99e559cef56416a3@Chaos1.DE>
References: <ffaabb4676ab075beb4b6d041ec280c4@Chaos1.DE>
<4332C38E.5040807@brandywine.com>
<72c14f47f1dca0ae99e559cef56416a3@Chaos1.DE>
Axel Rau wrote:
> Thank you for responding, Daryl,
>
> Am 22.09.2005 um 16:45 schrieb Daryl Richter:
>
>> Axel Rau wrote:
>>
>>> Hi SQLers,
>>> I have a fk from address to network and try to update the foreign key
>>> column to point at the network, "it belongs to":
>>> CREATE TABLE network (
>>> id cidr PRIMARY KEY , -- 'PK, ,IPv4/6 Network address'
>>> )
>>> CREATE TABLE address (
>>> id inet PRIMARY KEY , -- 'PK of IPv4/6 host address'
>>> network cidr NOT NULL -- 'FK to Network table'
>>> REFERENCES network ON DELETE CASCADE ON UPDATE
>>> CASCADE
>>> )
>>> I tried (using the WHERE clause to eliminate the addresses were no
>>> corresponding net exists):
>>
>>
>> But you can't insert a row in address w/o a valid network.id? That's
>> what the fk ensures.
>>
>> Perhaps you could elaborate more? Are you trying to *put* on the fk
>> and you currently have bad data?
>
> The fk requires a corresponding row in network. But my update tries to
> reference the right network, that one where the ip address belongs to.
I'm still not understanding what you're trying to do, perhaps its a
language issue. :) Let me try again.
I built your schema and inserted some rows:
insert into network( id ) values( '10.1' );
insert into address( id, network ) values( '10.1.0.1', '10.1' );
insert into address( id, network ) values( '10.1.0.2', '10.1' );
insert into address( id, network ) values( '10.1.0.3', '10.1' );
I then select from network:
id
-----------
10.1.0.0/16
and from address:
id network
-------- -----------
10.1.0.1 10.1.0.0/16
10.1.0.2 10.1.0.0/16
10.1.0.3 10.1.0.0/16
Why do you now want to update address.network? They are already
pointing to the right network, aren't they?
I think if you provide some sample data we can figure this out.
>
>>
>>> UPDATE address
>>> SET network = (SELECT N.id WHERE A.id << N.id)
>>> FROM address A, network N
>>> WHERE A.id << N.id;
>>
>>
>> This also makes no sense. For starters, << is "bitwise shift left" ...
>
> I'm using 8.0.3 and there are some new operators related to inet and
> cidr data types.
> On page 157, I found "<<" as address/network "is contained in" network.
>
> Finding the net where an address belongs to works as:
> SELECT id FROM network WHERE inet '$p_ipSource' << id;
>
Ahh, ok. see above.
> Axel
>
> Axel Rau, Frankfurt, Germany +49-69-951418-0
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 5: don't forget to increase your free space map settings
--
Daryl
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-sql@postgresql.org
Cc: daryl@brandywine.com
Subject: Re: Updating cidr column with network operator
In-Reply-To: <43331359.1020703@brandywine.com>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox