We present SQLT-Web, a Web-enabled intelligent teaching system for the SQL database language. The system observes students’ actions and adapts to their knowledge and learning abilities. Constraint-Based Modelling is used to model students. We describe the system's architecture in comparison to architectures of other existing Web-enabled tutors. All tutoring functions are performed on the server side, and we explain how SQLT-Web deals with multiple students. An initial evaluation of SQLT-Web has been done in a database course in May 1999. The students have enjoyed the system’s adaptability and found it a valuable asset to their learning.