DB101, part of the Yangjie platform, is an online learning course developed to help people in their quest to become proficient in using databases. The course is divided into several levels, each offering different levels of difficulty and covering different aspects related to database management, such as structured query language (SQL), access management, and data model design. The lessons are provided in an engaging and interactive manner, in order to ensure users can absorb and understand the concepts quickly. There are also various practice exercises, quizzes, and assignments for users to complete, allowing them to test their knowledge and skills. DB101 also provides detailed video tutorials and references, as well as a library of useful resources.