Post DB Management?

Hello experts.

I am writing this topic to understand more concepts about WP.

Before saying detailed question, I want give an example I want make it.

It is an example of a post. The post have contents and 3 Buttons (recomment, wish, buy)
And records of pusing these button shows on this post near button.
———————————————————–

< Post Contents>

[recommend] – 76, [wish it ] – 20, [buy it ] – 50
———————————————————–

At this point, I have questions.

1. How connect a number of clicking the button of users to a DB of this post?
: I used to use just default theme, so I don’t understand concept of WP.
(I have a little experience to manage mysql using other web tools)

2. How show off the records of a number of clicking.
: It seems to display results of DB to post.
Then, it is suppose to need a html code being able to connect to DB.

Please help me to understand more.

Regards,
gungs