rallport — 2011-06-05T08:42:20-04:00 — #1
I'm wondering if anyone could help with the following issue, as it turns out my issue is more complicated than I originally thought.
Basically, I have come up with a small database design to allow me to store product attributes, with price changes/stock level. So I could store an attribute for a product that adds £10 to the price and has 10 stock. See below:
However, what I'm having more of an issue with is storing combinations of attributes for stock levels. I've tried a few links tables, but everything seems to get very messyt pretty quickly. Is my original design (above)?
Any suggestions greatly appreciated.
r937 — 2011-06-05T09:29:16-04:00 — #2
do a search for entity-attribute-value (EAV) and you will see that many people struggle with this
it's not you, it's the hopelessly overgeneralized design
oddz — 2011-06-05T12:19:17-04:00 — #3
Here is a design you can try instead. It is rather complex but provides the ability to specify distinct pricing per physical item without being to repetitive.
products (think of this as a abstract bucket that groups physical products ie. part numbers).
- products_id (product physical item belongs to)
- products_id (product attribute corresponds to)
- attribute (name of attribute for products such as; color, size, weight, etc)
- weight (ordering when product has more then a single attribute)
- product_attributes_id (attribute value corresponds)
- attribute_value (value of attribute for color ie. red, blue, yellow, etc)
- product_part_numbers_id (physical item)
- product_attribute_values_id (attribute value)
Distinct pricing, stock info and attribute value combinations can now be specified per physical item (part_number).
ibazz — 2011-06-23T11:38:56-04:00 — #4
oddz, can I trouble you to explain the realtionship between the top two tables. I ain't getting it yet. (I understand the others )
What I mean is:
if I sell a product, it can have only one price so that would be a 1:1 relationship
if I sell a product that comprises others (eg big mac meal has a burger, fries and drink), the relationship is still 1:1 innit?
or is this a category : subCategory relationship?
| 1 | Menswear |
| 1 | Trousers |
| 2 | Socks |
| 1 | 1 | material | 1 |
| 1 | 1 | Linen |
If that is correct, I am confused as to why product_attributes is related to the products table and not, the product_part_numbers table