How to pull data from different mysql databases and display it (using pdo mysql) based on user clicking a predefined link on the webpage

Okay, so I am still learning PHP and pdo mysql, so what I am really looking for here is guidance\examples on basic principles of how to achieve my goal, this way I can make changes down the road on my own.

What I already have is a website where users (public users, no logins) will visit the page and can see the latest News from my database. As an example, if they load the page, it will display all news in the database named ‘nov15_announce’ and display it in descending order by date, and it limits it to the most recent 5.

Currently, I have links at the top of the page that they can click to see previous months announcements. When they click the link, it loads a separate webpage that I created with modified code to display data from that particular database. So, when they click “September” link, it loads the webpage that pulls data from the database named ‘sep15_announce’. When they click “October” link it takes them to the webpage that pulls data from the database named ‘oct15_announce’, etc…

What I would like to be able to do is instead of having multiple webpages with their own pdo code specifically for that database, have one webpage, that pulls & displays data based on the user selecting a link such as “September”, “October”, “November” etc etc…

Hopefully, I have thoroughly explained my intent. I am looking forward to learning!
Thanks in advance!