Developing the Subscription Mechanism
You learned in earlier lessons that planning is the most important aspect of creating any product. In this case, think of the elements you will need for your subscription mechanism:
A table to hold email addresses
A way for users to add or remove their email addresses
A form and script for sending the message
The following sections will describe each item individually.
Creating the subscribers Table
You really need only one field in the subscribers table: to hold the email address of the user. However, you should have an ID field just for consistency among your tables, and also because referencing an ID is a lot simpler than referencing a long email address in where clauses. So, in this case, your MySQL query ...