This defines a task db:populate that creates an example user with name and email address replicating our previous one, and then makes 99 more. The line

ensures that the Rake task has access to the local Rails environment, including the User model (and hence User.create!). Here create! is just like the create method, except it raises an exception (Section 6.1.4) for an invalid user rather than returning false. This noisier construction makes debugging easier by avoiding silent errors. With the :db namespace as in Listing 9.30, we can invoke the Rake task as follows:  

After running the Rake task, our application has 100 sample users, as seen in Figure 9.9. (I’ve taken the liberty of associating the first few sample addresses with photos so that they’re not all the default Gravatar image.)