How to seed your rails database with faker for testing

Adebola Adeniran
3 min readJun 13, 2020

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.

Database schema

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.

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.

# generate 20 users
(1..20).each do |id|
id: id, # each user is assigned an id from 1-20
password: "password", # issue each user the same password
password_confirmation: "password",
role: %w[customer admin agent].sample # a user can have only one of these roles

The Faker attributes you can use are all available from the faker GitHub page.

role: %w[customer admin agent].sample

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.

# create 10 tickets in DB
(1..10).each do |id|
id: id,
user_id: rand(1..20), # we have userIds between 1 and 20. Assign a ticket to a user randomly
status: %w[opened in_progress completed].sample,
request: Faker::Lorem.paragraphs # generate a fake paragraph
user_id: rand(1..20)

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.

# create comments in DB. Comments belong to tickets
(1..10).each do |id|
id: id,
user_id: rand(1..20),
comment: Faker::Lorem.sentence(word_count: 3),
user_name: User.find(rand(1..20)).name,
ticket_id: rand(1..10),
user_role: %w[customer admin agent].sample

Once done, simply run

rails db:seed

You can check that everything went well by checking your rails console.



Adebola Adeniran

Chief of Staff at Moni (YC W22) | Developer Advocate Building on Tezos