SQL is one of the most important skills for any programmer be it a Java, C++, Python, JavaScript, or Ruby developer. Almost 95% of the Java applications use a relational database in their back-end and almost all web applications use the database. In recent years, one of the most common ways to learn any programming skill is online, at your comfort of the office or home and SQL is no different. Learning SQL online has another advantage of a quick head start because you don't need to install a database and create tables to write some SELECT queries. The installation and setup are definitely a tough part for beginners and I have gone through that pain every time I have to learn a new database.