Re: Function PostgreSQL 9.2

On 4 May 2016 at 01:18, Melvin Davidson <melvin6925(at)gmail(dot)com> wrote:

>
>
> On Tue, May 3, 2016 at 1:21 AM, David G. Johnston <
> david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
>
>>
>>> Well.. I don't need to add a constraint if I already have a default
>>> value, that's right...
>>>
>>
>> Wrong
>>
>> David J.
>>
>
> What you need is a TRIGGER function & TRIGGER that will select and assign
> the next users_code based on company_id.
> I'm not going to write the whole thing for you, but here is part of the
> trigger function logic.
>
> eg: IF NEW.company_id = 1 THEN
> NEW.users_code = NEXTVAL(c1_users_code_seq);
> ELSEIF NEW.company.id = 2 THEN
> NEW.users_code = NEXTVAL(c2_users_code_seq);
> ELSEIF NEW.company.id = 3 THEN
> NEW.users_code = NEXTVAL(c3_users_code_seq);
> ...
> ...
> ELSE
> < something bad happened because NEW.company_id was not valid
> ?
> END IF;
>
>
>

Do I have to have one sequence peer company_id ? There will be thousands..
isn't there a better way to do that?

> Seriously, get yourself the books I have recommended and study them
> BEFORE you continue attempting to design your database.
> You need a firm understanding of logical design & flow, otherwise you will
> be wasting your time.
>

That's what I'm doing.. Studying.. asking for some help to get a better
understand.... isn't this the purpose of this mail list?