title: How to arrange my entities so a Shop can have Products from a Supplier?
body: <p>I'm creating a Platform where Suppliers have Products that Shops can choose, add to their Shop and start selling. </p>
  
  <p>My situation is as follows:</p>
  
  <ul>
  <li>A Supplier can have many Products (for example: 'T-shirt', 'Iphone Case') (<strong>Supplier->product: One-To-Many</strong>)</li>
  <li>A Supplier Product can have many SKU (for instance: 'T-shirt Small Black', 'T-Shirt Small White') (<strong>Product->sku: One-To-Many</strong>)</li>
  <li>A Shop should be able to "copy" Products from the Supplier, So would I need a Shop_Product table here? (<strong>Shop->Product: One-To-Many</strong>)</li>
  </ul>
  
  <p>The main problem is that my Shop has SKUs from the Supplier but no Products. If I add a Shop_Products table representing a relationship, then how should I "couple" my Shop_Skus to that table?</p>
  
  <h2>Should I add a Shop_Product table, next to the existing Shop_Sku table?</h2>
  
  <p>My current database structure is depicted in the diagram below:</p>
  
  <p><a href="https://i.stack.imgur.com/W9Qy7.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/W9Qy7.png" alt="enter image description here"></a></p>
  
  <p>With a Shop_Product column it would look like this</p>
  
  <p><a href="https://i.stack.imgur.com/PX7Cw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/PX7Cw.png" alt="enter image description here"></a></p>
  
  <p>But then there is no relationship between the Shop_Product and the Shop_Sku which makes this structure irrelevant.</p>