title: Nullable Foreign Key bad practice?
body: <p>Let's say you have a table Orders with a foreign key to a Customer Id. Now, suppose you want to add an Order without a Customer Id, (whether that should be possible is another question) you would have to make the foreign key NULL... Is that bad practice or would you rather work with a link table between Orders and Customers? Although the relationship is 1 to n, a link table would make it n to n. On the other hand, with a link table, I don't have those NULLS anymore... </p>
  
  <p>There won't actually be a lot of NULL's in the database, because a record with a foreign key to NULL is just temporarily until a customer for the order is added.</p>
  
  <p>(In my case it isn't an Order and a Customer).</p>
  
  <p>EDIT: What about a unassigned Customer to link to?</p>