Taking a database class is valuable no matter what programming language you are planning to specialize in. What you will need to know is mostly independent of the programming language. You will learn how to define a database to properly store real world data in a manner that is both useful and non-redundant. You will learn the commands (SQL commands that are mostly common to all relational database systems) to modify, maintain and retrieve data from that database. Pay attention to the part about normalization.
Definitely. When you’re in already in the programming or IT industry, you will be doing programs wherein database serves as the backbone. Take for example when you need to do a program for bank operations, you need to have knowledge on how about database and MySQL is one of the most basic and yet efficient tool that you should know how to use.