Re: database model tshirt sizes - Mailing list pgsql-performance

So a default value for all products would be size:"all"

for example, the same tshirt shop also sells cdroms.

It size attribute would be to place it to be :"all". (because we cannot
place an uniqe index on null values)

But the industry evolves and so in time the same cdrom is now available for
pc and playstation.

So i would like to have it as 1 productid but with different attributes: pc
(with quantity 5) and playstation (with quantity 3).
So when I do an insert for this 2 products with 1 productid it would be
like:

insert into versions (productid,size,quantity) values (345,'pc',5);
insert into versions (productid,size,quantity) values (345,'playstation',3);

if however the product existed we get an error:

because the default value version "all" did also exist and is now obsolete

population versions:
================

productid: 123, versionid: 1, color: 'black', size: 'all', quantity: 11
productid: 442, versionid: 2, color: 'yellow', size: 'l', quantity: 1
productid: 442, versionid: 2, color: 'yellow', size: 's', quantity: 4
productid: 442, versionid: 2, color: 'red', size: 'xl', quantity: 9
productid: 442, versionid: 2, color: 'blue', size: 's', quantity: 0
productid: 345, versionid: 3, color: null, size: 'all', quantity: 15
productid: 345, versionid: 3, color: null, size: 'pc', quantity: 5
productid: 345, versionid: 3, color: null, size: 'playstation', quantity: 3

WOULD HAVE TO BE:

population versions:
================

productid: 123, versionid: 1, color: 'black', size: 'all', quantity: 11
productid: 442, versionid: 2, color: 'yellow', size: 'l', quantity: 1
productid: 442, versionid: 2, color: 'yellow', size: 's', quantity: 4
productid: 442, versionid: 2, color: 'red', size: 'xl', quantity: 9
productid: 442, versionid: 2, color: 'blue', size: 's', quantity: 0
productid: 345, versionid: 3, color: null, size: 'pc', quantity: 5
productid: 345, versionid: 3, color: null, size: 'playstation', quantity: 3

ALSO:

what is versionid used for?


----- Original Message -----
From: <me@alternize.com>
To: "NbForYou" <nbforyou@hotmail.com>
Cc: <pgsql-performance@postgresql.org>;
<pgsql-performance-owner@postgresql.org>
Sent: Sunday, March 19, 2006 3:37 PM
Subject: Re: [PERFORM] database model tshirt sizes


> another approach would be:
>
> table product:
>> productid int8 PK
>> productname charvar(255)
>
> table versions
>> productid int8 FK
>> versionid int8 PK
>> size
>> color
>> ...
>> quantity int4
>
> an example would be then:
>
> table product:
> - productid: 123, productname: 'nice cotton t-shirt'
> - productid: 442, productname: 'another cotton t-shirt'
>
> table versions:
> - productid: 123, versionid: 1, color: 'black', size: 'all', quantity: 11
> - productid: 442, versionid: 2, color: 'yellow', size: 'l', quantity: 1
> - productid: 442, versionid: 2, color: 'yellow', size: 's', quantity: 4
> - productid: 442, versionid: 2, color: 'red', size: 'xl', quantity: 9
> - productid: 442, versionid: 2, color: 'blue', size: 's', quantity: 0
>
>
> that way you can have more than 1 quantity / color / size combination per
> product and still have products that come in one size. so instead of only
> using a 2nd table for cases where more than one size is available, you
> would always use a 2nd table. this probably reduces your code complexity
> quite a bit and only needs 1 JOIN.
>
> - thomas
>
>
>
> ----- Original Message -----
> From: "Patrick Hatcher" <PHatcher@macys.com>
> To: "NbForYou" <nbforyou@hotmail.com>
> Cc: <pgsql-performance@postgresql.org>;
> <pgsql-performance-owner@postgresql.org>
> Sent: Sunday, March 19, 2006 2:59 PM
> Subject: Re: [PERFORM] database model tshirt sizes
>
>
>> We have size and color in the product table itself.  It is really an
>> attribute of the product.  If you update the availability of the product
>> often, I would split out the quantity into a separate table so that you
>> can
>> truncate and update as needed.
>>
>> Patrick Hatcher
>> Development Manager  Analytics/MIO
>> Macys.com
>>
>>
>>
>>             "NbForYou"
>>             <nbforyou@hotmail
>>             .com>                                                      To
>>             Sent by:                  <pgsql-performance@postgresql.org>
>>             pgsql-performance                                          cc
>>             -owner@postgresql
>>             .org                                                  Subject
>>                                       [PERFORM] database model tshirt
>>                                       sizes
>>             03/18/06 07:03 AM
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Hello,
>>
>> Does anybody know how to build a database model to include sizes for
>> rings,
>> tshirts, etc?
>>
>>
>> the current database is built like:
>>
>> table product
>> =========
>>
>> productid int8 PK
>> productname charvar(255)
>> quantity int4
>>
>>
>> what i want now is that WHEN (not all products have multiple sizes) there
>> are multiple sizes available. The sizes are stored into the database. I
>> was
>> wondering to include a extra table:
>>
>> table sizes:
>> ========
>> productid int8 FK
>> size varchar(100)
>>
>>
>> but then i have a quantity problem. Because now not all size quantities
>> can
>> be stored into this table, because it allready exist in my product table.
>>
>> How do professionals do it? How do they make their model to include sizes
>> if any available?
>>
>>
>> ---------------------------(end of broadcast)---------------------------
>> TIP 9: In versions below 8.0, the planner will ignore your desire to
>>       choose an index scan if your joining column's datatypes do not
>>       match
>>
>
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 6: explain analyze is your friend
>