Re: Conditional INSERT

On 3/15/19 11:54 AM, basti wrote:
> this is a dns database, and the client is update the _acme-challenge for
> LE certificates. I don't want that the client can insert "any" txt record.
> the client should only insert data if the hostname start with
> _acme-challenge. i have no control on client.
>
> i have try this rule but the server reject this with a endless loop:

To borrow a quote:

"I had a problem so I decided to use a rule, now I have two problems."

Do not use a rule. As suggested upstream use a BEFORE INSERT trigger,
you will be a lot happier.

>
> CREATE RULE insert_acme AS ON INSERT TO t_dnsadmin_records_txt
> WHERE NEW.hostname like '_acme-challenge%'
> DO INSERT INTO t_dnsadmin_records_txt VALUES (
> NEW.domainid,
> NEW.hostname,
> NEW.txtdata
> );
>
>
> On 15.03.19 19:17, Michael Lewis wrote:
>> On Fri, Mar 15, 2019 at 10:55 AM basti <mailinglist(at)unix-solution(dot)de
>> <mailto:mailinglist(at)unix-solution(dot)de>> wrote:
>>
>> Hello,
>>
>> I want to insert data into table only if condition is true.
>> For example:
>>
>> INSERT into  mytable (domainid, hostname, txtdata)
>>   VALUES (100,'_acme.challenge.example', 'somedata');
>>
>>
>> Alternative to a trigger implementation, if you are generating that
>> INSERT statement, you can change it to use a sub-select or CTE that
>> contains no values if the domainid isn't what you like. If you want it
>> to fail with error, you could add a check constraint. We might need more
>> context on what you are doing and why to give good advice.
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com