I built a Customer Support System a few days ago and started to think of a way to seed my rails database with random data for testing without having to manually type in the data. This may not be the best way to do it, but it works and allows you to test your application.
We want a way to generate users that have tickets and also have comments without having to manually type in a value for each field.
Let's start with the basic schema of the DB.
Our Database, schema and migrations have already been generated and the main focus here will be on seeding the database.
First, install the faker gem by adding it to your list of gems in your gemfile.
gem 'faker'
then run 
bundle install
Once done, head into your seeds.rb file inside the db directory. In here, require the faker gem at the beginning.
require 'faker'
Next, let's create Users using fake data from the 
faker gem
.
The Faker attributes you can use are all available from the faker GitHub page.
role: %w[customer admin agent].sample # a user can have only one of these roles
The line above may look a little strange — we’ve designed our model to only accept one of the values in [“customer”, “admin”, “agent”] as the
values assigned to role for users. calling 
.sample
on the array causes the code to select one of the three possible values.
I’ve added some comments using the # symbol beside the lines.
Next, let’s create Tickets. Remember that each ticket belongs to a User. As such, we’ll need to find a way to assign tickets to users randomly.
The line above is used to generate a random number between 1 and 20. Recall that our users were assigned Id’s between 1 and 20.
Finally, let’s generate comments that belong to a User and is tied to a ticket.
Once done, simply run
rails db:seed
You can check that everything went well by checking your rails console.