We are going to build an example application, so that you will be able to give all this a try. In this case we are going to build a website monitoring program, to help you test websites, keep reports of what has been done in each one, and so on. Firstly, let's set some objectives. These are:
To manage one or more remote websites with a minimum of human intervention
To run regular tests on the remote sites
To generate reports on demand, giving details of the site and of tests conducted
So, the first thing you will need is a database of websites to check. Set up a database called websites in MySQL or whatever RDBMS you're using. You can get all the SQL necessary to create the tables needed in your application in the chapter Appendix. Copy it and execute the SQL into your database in order to generate the database structure.
Summarizing it a little you will have a site table, to keep information about your sites, a hosts table associated to a domains table, and...