Try out Bags now! (beta release)
Bags is a new drag-and-drop environment for learning about database query design and relational operations. It is currently under development at James Madison University by Jason Gorman, Sebastian Gsell, and Chris Mayfield. See our SIGCSE 2014 Paper and Slides for more details.
Relational algebra provides a theoretical foundation for how modern database management systems optimize and execute queries. Its main concepts are based on set theory and first order logic, which can be challenging for students to learn due to their abstract nature. Bags provides a hands-on way for engaging with these concepts. Inspired by educational tools like Scratch (MIT) and Snap! (Berkeley), we have designed a new type of visual programming for the teaching of relational algebra. Students formulate algebraic queries by snapping together graphical blocks that represent data sets and relational operators, resulting in an interactive visualization of the underlying concepts.
Check out Lab11 from JMU's CS 101 for an example classroom activity that features Bags. Additional teaching materials are under development and will be made available soon. Stay tuned!