appending to rake db:seed in rails and running it without duplicating data

user_334545 0
Viewed 16296

Rake db:seed populates your db with default database values for an app right? So what if you already have a seed and you need to add to it(you add a new feature that requires the seed). In my experience, when I ran rake db:seed again, it added the existing content already so existing content became double.

What I need is to add some seeds and when ran, it should just add the newest ones, and ignore the existing seeds. How do I go about with this? (the dirty, noob way I usually do it is to truncate my whole db then run seed again, but that's not very smart to do in production, right?)

seeding ruby-on-rails-3 ruby-on-rails ruby
9 Answers

A cleaner way to do this is by using find_or_create_by, as follows:

User.find_or_create_by_username_and_role(
  :username => "admin",
  :role => "admin",
  :email => "me@gmail.com")

Here are the possible outcomes:

  1. A record exists with username "admin" and role "admin". This record will NOT be updated with the new e-mail if it already exists, but it will also NOT be doubled.
  2. A record does not exist with username "admin" and role "admin". The above record will be created.
  3. Note that if only one of the username/role criteria are satisfied, it will create the above record. Use the right criteria to ensure you aren't duplicating something you want to remain unique.
user_3415830

Another alternative is to use the #first_or_create.

categories = [
    [ "Category 1", "#e51c23" ],
    [ "Category 2", "#673ab7" ]
]

categories.each do |name, color|
  Category.where( name: name, color: color).first_or_create
end
user_70073110
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