Andy Shellam writes:
> I know about the <> and !=, for some reason != has always made better sense
> to me to read, so I tend to write it that way.
Yeah, a lot of people prefer != ... that's why we provide it as an
alias for <>. There's no functional difference.
regards
Hi Tom and Scott,
>
> I think your real problem is that you're trying to use "= NULL" and
> "!= NULL" where you should say IS NULL or IS NOT NULL.
Argh such a school-boy error! This is the first bit of database programming
I've done for about 2 months, and I hadn't switched my C++ brain off.
Andy Shellam writes:
> With the above in mind, I decided on the following check to enforce this:
> (state = 'Unconfirmed'::client.order_state AND invoice_id = NULL) OR (state
> != 'Unconfirmed'::client.order_state AND invoice_id != NULL)
> However PostgreSQL (8.4.2) converts this to the followi
On Mon, Jan 11, 2010 at 12:49 PM, Andy Shellam
wrote:
> With the above in mind, I decided on the following check to enforce this:
>
> (state = 'Unconfirmed'::client.order_state AND invoice_id = NULL) OR (state
> != 'Unconfirmed'::client.order_state AND invoice_id != NULL)
Nothing can = null. an
Hi,
I notice this had been raised as a bug (and subsequently over-ruled) so I'm
asking how I can achieve the following business rule.
I have an order table which has an invoice_id column that links to an invoice
table (an order can only have 1 invoice, but one invoice can have multiple
orders.
