Relationships integrity

[gowans07]

I'm trying to create a database to store product and customer information.
An item have many batch numbers (batch ID)
a batch number can only belong to one item

an item can be in many products
a product contains many items

an order can contain many products
a product can be in many orders

a customer can have many orders
an order can only be for one customer

from this information i have created the following relationships. see attachment
Is this all correct?? i think the relationship between batch ID in tbl_batch is wrong??
Cheers in advance

 

[jdraw]

There are existing data models at www.databaseanswers.org
Here is one specific to Customers and Products
http://www.databaseanswers.org/data_models/customers_and_products/index.htm

It may not be exactly what you need -- it may have more or less detail -- but it should help you with ideas of how tables are/could be related.
Good luck.