title: Entity Relation Diagrams
body: <p>I am doing a project on Inventory Management System for office managing office products. As a first step, I designed the ER diagram:</p>
  
  <p><a href="https://i.stack.imgur.com/2H9Fv.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2H9Fv.png" alt="enter image description here"></a></p>
  
  <p>Can anyone review and suggest changes?</p>
  
  <p>I am really doubtful at the <strong>Purchase Table</strong> and its relation to <strong>Product Table</strong> and <strong>Warranty Table</strong>. Suppose I purchased 2 monitors, 3 CPU's in one purchase (5 products), then how can I trace those products in the product table. And how can I claim warranty for those items individually (Imagining the warranty for each product is different)</p>