title: how database relationship work in databases
body: <p>I have started a new job recently as .Net Developer, in that for the projects that I am working on requires strong understanding of relationships like 
  1-N, 1-1 and N-N. I have completely understood 1-1 relationship with real life example like In a <strong>Tablets</strong> and <strong>Billing</strong> table if <strong>Billing</strong> table has TabletId as a foreign key then there is 1-1 relationship between them, but talking about 1-N and N-N relationship regarding same tables how the real life example can be put forward. I have not completely understood.</p>
  
  <p>Tablet </p>
  
  <p>TabletId
  Name
  description
  Maker
  ExpiryDate</p>
  
  <p>Billing</p>
  
  <p>BillingId
  TabletId F.K
  TDate</p>
  
  <p>so from above table structure it is clear that one bill can have one tablet only. but if i want one bill can have multiple tablets then how will i achieve that. </p>
  
  <p>Please give me example of <strong>Tablets</strong> and <strong>Billing</strong> table for 1-N and N-N relationships</p>