I am trying to design and build an orders management database for a clothing wholesaler.

Has anyone got any ideas on what entities i should have.

I thought:

Clients (Customer Details)
Orders (Inc. order date, ship via etc)
Order Details (sizes, quantity of orders per size)
Product Details (Product Code, colour, size, stock numbers per size)
Catergories (Shorts, Jackets, Jeans etc)
Suppliers (Supplier Information)
Delivery (Delivery Method etc)

However, loads of problems when i come to planning the sizes part. I have different product catergories with different sizes

And when i do the order details table, i need to enter order quantities for each different size for one clothing unit.

Any ideas?

I would also ideally want to link the order details and products tables by the product code number. I.e. When filling out an order In the order details table i want to type in the product code then have information from the product table automatcially fill in the gaps in the order details table, such as unit price, colour etc.

Hope you understand and can help me!!!

Thanks for your time