ActiveRecord::NoDatabaseError

ActiveRecord::NoDatabaseError is a standard error message that you might encounter while using Ruby on Rails. This error message indicates that your application is unable to connect to a database because it cannot find it or the database is not configured properly.

Here's an example of how you might encounter this error:

ActiveRecord::NoDatabaseError: FATAL: database "my_app_development" does not exist

This error message is telling you that your application is looking for a database called "my_app_development" but cannot find it.

To fix this error, you should check your database configuration in your Rails application's config/database.yml file. Make sure that the database name, username, and password are all correct.

If you have already set up your database correctly, the error could be due to a connectivity issue. Check your network settings, firewall, and other factors that could be affecting your database connection.

In summary, ActiveRecord::NoDatabaseError is a common error message indicating that your application cannot connect to a database. Check your configuration and connectivity to resolve the issue.