Someone was kind enough to report that the Mondial database, which is used for all the SQL practice exercises, was empty – i.e., it was not loaded correctly as part of the virtual machine (VM)’s software installation.

Fortunately, there is a simple fix to resolve this issue. Open the Terminal in the VM and execute the following command in the directory with the setup script used for the software installation (the directory is probably called “vm” or “vm-master”):

db/restore.sh databases.yaml

The restore script will drop (i.e., delete) all the existing PostgreSQL databases and recreate them, and I’ve corrected the original mistake that prevented the Mondial database from being loaded correctly.

Note: If you’ve already started the SQL programming exercise (PEX), then talk to me before running the prior command. It destroys all the existing data, which should not be an issue, but might cause a few of your queries not to work when testing them locally. (The first few queries assume that you’ve created various tables, which will be lost when the existing databases are dropped.)