On Thu, 2016-09-01 at 12:28 +0300, Michelle Konzack wrote:
> Hello to all,
>
> after a period of silence from Debian, Courier, PHP and PostgreSQL
> I am
> half back and running into a problem... :-/
>
> I need a table with an UNIQUE CustomerID which is working fine...
>
> ...BUT I need also a second column with a count,
> which must be UNIQUE
> inside the CustomerID.
>
> In clear this:
>
> CustID Count
> 1 1
> 1 2
> 1 3
>
> 2 1
> 2 2
>
> 3 1
> 3 2
> 3 3
> ...
>
> How to do this?
>
> Thanks in avance
>
> --
> Michelle Konzack ITSystems
> GNU/Linux Developer 0033-6-61925193
>
>
Hi,
(I wouldn't name a column "count").
SELECT MAX(count_er) FROM my_customer_table WHERE cust_id = $1;
Add one to the result. Do INSERT.
As SELECT MAX is a GROUP function it will return zero if the cust_id
doesn't exist.
HTH,
Rob