Hi,
I've got this chain of tables:
ship --> (id_ship) --> cabin_type --> (id_cabin_type) --> cabin_category
--> (id_cabin_category) --> cabin
The 'cabin' table has (cabin_number, id_cabin_category ref. cabin_category)
How can I guarantee unicity of cabin_number per ship?
For now I adde
On Wed, Mar 3, 2010 at 7:02 AM, Louis-David Mitterrand
wrote:
> What is the best solution? Adding an id_ship to 'cabin'? Or check'ing
> with a join down to 'ship'? (if possible).
Can you post simplified table definitions for the relations involved?
--
Regards,
Richard Broersma Jr.
Visit the
On Wed, Mar 03, 2010 at 07:14:29AM -0800, Richard Broersma wrote:
> On Wed, Mar 3, 2010 at 7:02 AM, Louis-David Mitterrand
> wrote:
>
>
> > What is the best solution? Adding an id_ship to 'cabin'? Or check'ing
> > with a join down to 'ship'? (if possible).
>
> Can you post simplified table defi
On Wed, Mar 3, 2010 at 7:19 AM, Louis-David Mitterrand
wrote:
> CREATE TABLE cabin_type (
> CREATE TABLE cabin_category (
> CREATE TABLE cabin (
I'm just curious about a few things.
1) What is the difference between a cabin_type and a cabin_category.
2) Does each ship have an exclusive set
On Wed, Mar 03, 2010 at 07:29:22AM -0800, Richard Broersma wrote:
> On Wed, Mar 3, 2010 at 7:19 AM, Louis-David Mitterrand
> wrote:
>
> > CREATE TABLE cabin_type (
>
> > CREATE TABLE cabin_category (
>
> > CREATE TABLE cabin (
>
> I'm just curious about a few things.
>
> 1) What is the differ
On Wed, Mar 3, 2010 at 7:38 AM, Louis-David Mitterrand
wrote:
> Each ship is different and has specific cabin types and categories. Of
> course there is some overlap between ships but I thought it simpler (or
> more elegant) to use that hierarchy. Maybe my schema is wrong?
I'm probably ignorant
Hello,
I would have designed as ship > cabin (PK of ship_id, Cabin_id)
And a separate chain of cabin_type > cabin_category > cabin
Type, and category are group classifiers and shouldn't be used to define the
uniqueness of a cabin.
Take an example where the cabin category and type are defined
- Original Message -
From: "Louis-David Mitterrand"
To:
Sent: Wednesday, March 03, 2010 3:38 PM
Subject: Re: [SQL] check constraint on multiple tables?
On Wed, Mar 03, 2010 at 07:29:22AM -0800, Richard Broersma wrote:
On Wed, Mar 3, 2010 at 7:19 AM, Louis-David Mitterrand
wrote:
On Wed, Mar 03, 2010 at 10:03:05AM -0600, Little, Douglas wrote:
> Hello,
>
> I would have designed as ship > cabin (PK of ship_id, Cabin_id)
> And a separate chain of cabin_type > cabin_category > cabin
Ah, now I'm having second thoughts about my schema ;)
> Type, and category are group classi
Hey Louis,
Ship rooms are just like Hotel rooms. There are lots of ways to describe. But
there needs to be some consistency between the classifiers for them to have any
meaning.
A junior suite should mean the same thing regardless of the ship it's on.
Doug
-Original Message-
Fro
On Wed, Mar 03, 2010 at 04:05:43PM -, Oliveiros wrote:
>
> As your table names seem to imply, type and category are cabin's
> characteristics , not ship characteristics.
> Am I right?
Yes and no :)
- I'm scanning cruise line web sites with a spider to collect prices so
I'm building cabin_
On Wed, Mar 03, 2010 at 10:13:48AM -0600, Little, Douglas wrote:
> Hey Louis,
>
> Ship rooms are just like Hotel rooms. There are lots of ways to
> describe. But there needs to be some consistency between the
> classifiers for them to have any meaning.
>
> A junior suite should mean the same th
Louis,
Interesting discussion. Always fun to think about real world stuff.
We have a similar problem for comparing hotel rooms.
So the issue is that you aren't originating the data, just classifying it.
I'd move toward a scheme where you reclassify the line marketing speak to
common lay terms
On Wed, Mar 03, 2010 at 10:29:44AM -0600, Little, Douglas wrote:
> Louis,
> Interesting discussion. Always fun to think about real world stuff.
Indeed.
> We have a similar problem for comparing hotel rooms.
> So the issue is that you aren't originating the data, just classifying it.
> I'd mov
Hi all,
is there a way (also strange) to define a trigger on a system table (for
example on pg_class)?
I tried but I got (as expected) a permission denied message...
Thanks
Gianvito Pio wrote:
> Hi all,
> is there a way (also strange) to define a trigger on a system table (for
> example on pg_class)?
No.
Andreas
--
Really, I'm not out to destroy Microsoft. That will just be a completely
unintentional side effect. (Linus Torvalds)
"If
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