Is this a good way to model address information in a relational database?

Question

I\'m wondering if this is a good design. I have a number of tables that require address information (e.g. street, post code/zip, country, fax, email). Sometimes the same a

Answer 1

In the case of orders, you would never want to update the address as the person (or company) address changed if the order has been sent. You meed the record of where the order was actually sent if there is an issue with the order.

The address table is a good idea. Make a unique constraint on it so that the same entity cannot have duplicate addresses. You may still get them as users may add another one instead of looking them up and if they spell things slightly differently (St. instead of Street) the unique constraint won't prevent that. Copy the data at the time the order is created to the order. This is one case where you want the multiple records because you need a historical record of what you sent where. Only allowing inserts and deletes to the table makes no sense to me as they aren't any safer than updates and involve more work for the database. An update is done in one call to the database. If an address changes in your idea, then you must first delete the old address and then insert the new one. Not only more calls to the databse but twice the chance of making a code error.