RA: A Relational Algebra Interpreter
RA is a relational algebra interpreter interface to SQL-based
database systems, ideal for teaching and learning.
The latest version of RA, called radb, is based on
Python 3. You will be automatically redirected to it website
in 15 seconds.
The earlier, Java-based version of RA, called ra, can
still be accessed
A note on what has (not) changed besides moving from Java to
- The new radb is more user-friendly and has much
better error reporting than the old ra.
- The new radb doesn't have some of the
old ra's limitations. For example, users don't
need write permission on a database to query, so it is easy
to set up exercises for multiple students using a single
- The new radb's relational algebra syntax is
backward-compatible with the old ra, but it also
has new features such as saving/restoring work to/from
files, and defining views (which allows complex queries to
be written in multiple steps).
Maintained by Jun Yang