Click on hyperlink and change to alert img icon to be save to database

Question

Hi, I am doing a web application. In this grid view is used to store the critical terms that user have defined it for their contract. At the alert column, there will be a hyperlink such that when user clicks on the hyperlink, it will become an image to be stored to database. May I know how shld I go abt doing it? And what data type shld I use? Thanks!

I am using 3-tier programming way to code out the project. Thanks!