Rails uses sqlite3 as the default database, but you can generate a new rails application with a database of your choice. Just add the -d option followed by the name of the database.

$ rails new MyApp -T -d postgresql

This is a (non-exhaustive) list of available database options:

• mysql
• oracle
• postgresql
• sqlite3
• frontbase
• ibm_db
• sqlserver
• jdbcmysql
• jdbcsqlite3
• jdbcpostgresql
• jdbc

The -T command indicated the testing suite of RSpec. We can write our automation test cases using this tool