A web-based tool developed to automatically correct conceptual database schema is presented. This tool has been integrated into a more general e-learning platform and is used to reinforce teaching and learning on introductory database courses. This platform assigns to each student a set of database problems selected from a common repository. The student has to design a entity-relationship schema and enter it into the system through a user friendly interface specifically designed for it. The correction tool corrects the design and shows detected errors giving advice of how to solve them. The student has the chance to send a new solution. These steps can be repeated as many times as required until a correct solution is obtained.