You need to create a service for the purpose of saving image in MySQL database.
There are many approaches through which you can get your job done. A google/bing search with some good keywords can yield 100s of good artcles on this topic.
However, for a step by step solution you can refer to following article which has proposed solution using PHP and MySQL-
Android Upload Image to Server Using PHP MySQL
You can refer to the video tutorial too.
In case you find any difficulties while implementing this, please let me know with the details of the issue.
Hope, it helps :)