Database design question

[smagdy]

Hi everybody...

Iam designing database that has categories for ex. like cars or mobiles.

so ive several categories like nokia, samsung, sony ericsson etc...

so there r lot of models in each category and every model have some info..

like nokia 9#*$! - size - weight - etc..

so my question is should i put every category (nokia, sony) in table
or all categories in one table?

Thanks in advance

[john_k]

First, you need to read up on relational database design. Here is a quick pass on some tables you would need:

CATEGORY 
 CategoryId 
 CategoryName 
 ParentCategoryId 
  
ATTRIBUTE 
 AttributeId 
 AttributeName 
  
ATTRIBUTEOPTION 
 AttributeOptionId 
 AttributeId 
 AttributeOptionName 
 PriceAmount 
 PricePercent 
 Weight 
  
MANUFACTURER 
 ManufacturerId 
 ManufacturerName 
  
ITEM 
 ItemId 
 ItemName 
 ManufacturerId 
 SKU 
 ManufacturerSKU 
 Weight 
  
CATEGORYITEM 
 CategoryItemId 
 CategoryId 
 ItemId 
  
ITEMATTRIBUTE 
 ItemAttributeId 
 ItemId 
 AttributetId 
  
ITEMATTRIBUTEOPTION 
 ItemAttributeOptionId 
 ItemAttributeId 
 AttributeOptionId 

So mobiles and cars would go into the Category table. Nokia, Ericsson, Samsung, and Sony would go into the Manufacturer table. Size goes into the Attribute table. Possible sizes go into the AttributeOption table. Sizes for a specific Item go into the ItemAttributeOption table. Weight goes into the Weight field of the Item table.

There are a hundred different ways to break down the smaller details. It all depends on what makes sense for your needs. If you have a lot of products and/or will be doing a lot of additions or updates, then you need to take time up front to get a good relational design. Otherwise the data maintenance will become extremely painful and expensive.

[henry0]

Unless you forecast many hundreds of items per cate
I will keep it simple (using PHP and MySQL)
have an auto incremented cat ID
then plug in all your cat
and when in need of a query you will do
... where id = $cat_id and cat=$cat or any query that allows for making use of a predefined cat and or ID

regards

Henry

[smagdy]

Well, thanks for reply...

maybe i wasnt clear in something...

my database will just have one thing of mobiles or cars..

so lets say just mobiles..

so should i make

Category
id
name

Model
id
name
size
weight
etc...

OR

Nokia
model_name
size
weight
etc...

Sony_ericsson
model_name
size
weight
etc...

Samsung
model_name
size
weight
etc...

so one big table or several smaller ones maybe 10 max 20.

Thanks again

[henry0]

Unless you are preparing for a VERY large number of items
I will use the first option