For those interested in the querying portion of Postgres guide and less on designing their application you can load an example database provided by us. This example database is used through the SQL section and allows you to follow along without having to have your own schema/data.
First you'll want to download the data, then load it:
curl -L -O http://cl.ly/173L141n3402/download/example.dump createdb pgguide pg_restore --no-owner --dbname pgguide example.dump psql --dbname pgguide
If you don't already have Postgres running locally you can use Heroku Postgres to provision a free database to use for development. Once you've provisioned a Heroku Postgres database you can load it with:
heroku pgbackups:restore DATABASE 'http://cl.ly/173L141n3402/download/example.dump'
Understanding the Schema
The schema contains an example set of products, purchases, and the users that made purchases. The basic layout of the tables and the relationship between them is laid out as: