[Rails] Various ways to write in seed files

• This is a reminder to yourself. If you understand how to create data in the basic form, you will probably get an image.

environment

Ruby 2.6.5 Rails 6.0.3

How to write this and that

① Create only one (basic)

seed.rb

User.create!(
   email: "[email protected]",
   name: "user1",
   passowrd: "password"
)

Create! Action for the model you want to create a record for. I will give the value of each column.

② Create multiple demo data

seed.rb

 users = User.create!([
  {nickname: "guest", email: "[email protected]", password: "guest1234"},
  {nickname: "guest2", email: "[email protected]", password: "guest5678"}, 
])

Prepare an array. It can be created by passing record data in the form of a hash to each element of the array.

③ Create multiple demo data (repetitive processing)

seed.rb

20.times do |n|
  User.create!(
  name: "guest#{n+1}",
  email: "guest#{n+1}@guest.com",
  password: "guest#{n+1}0000",
 )
end

Execute the create! Action multiple times using the times method. Implement different values in each record by including n in the value so that columns with uniqueness do not overlap.

④ Combine arrays

seed.rb

stations = ["Tokyo",
  "Yurakucho",
  "Shimbashi",
  "Hamamatsucho",
  "Tamachi",
  "Takanawa Gateway",
  "Shinagawa",
  "Osaki" ,
  "Gotanda",
  "Meguro",
  "Ebisu",
  "Shibuya",
  "Harajuku",
  "Yoyogi",
  "Shinjuku",
  "Shin-Okubo",
  "Takadanobaba",
  "Mejiro",
  "Ikebukuro",
  "Otsuka",
  "Sugamo",
  "Komagome",
  "Tabata",
  "Nishinippori",
  "Nippori",
  "Uguisudani" ,
  "Ueno",
  "Okachimachi",
  "Akihabara",
  "Kanda"]

stations.length.times do |i|
  Station.create!(
    name: stations[i]
  )
end

After preparing the array, iterate as many times as there are, and give the value of the array to the column. (I think I should be able to go with each, but for some reason it didn't work and I processed it with times) I used an array because I wanted to reuse this value for another column. (Specifically, when I made the demo data of the restaurant after this, I wanted to include the station name in the store name, so I chose this method)

⑤ Create a record including attributes nest

seed.rb

Item.create!(
  name: "sofa",
  produce: "Brand new",
  price: 8000,
  images_attributes: [{image: File.open('./app/assets/images/index_item01.png',)}]
  )

When the Item table nests the Image table and has a has_many relationship. Since images_attributes has multiple record data, create an array and give the record data of the Image table by hash in it.

⑥ Various combinations so far

seed.rb

10.times do |i|
  Shop.create!(
    name: "Fresh fish shop#{stations[i]}shop",
    address: addresses[i],
    capacity: 40,
    mainimage: File.open('./app/assets/images/shops/shop1_1.jpg'),
    maincontent: "We are waiting for you to prepare seafood directly from the production area!",
    likepoints: 0,
    station_ids: [i+1,i+2],
    introduces_attributes: [
      {subcontent: "You can enjoy your meal in the calm interior.",
        number: 1,
        subimage: File.open('./app/assets/images/shops/shop1_2.jpg')},
      {subcontent:"We recommend the seafood platter!",
        number: 2,
        subimage: File.open('./app/assets/images/shops/shop1_3.jpg')},
      {subcontent: "A talkative clerk is waiting for you!",
        number: 3,
        subimage: File.open('./app/assets/images/shops/shop1_4.jpg')}
    ]
  )
end

Multiple shop data are created using the array called stations. The shop table nests the introduces table, and I want to pass multiple records to the introduces table, so I pass an array in the form of a hash. It's not that complicated, surprisingly. (I don't know the cause, but this didn't work at first, and when I adjusted the indentation, something went wrong.

Summary

When I studied how the data was sent in the form, I understood a lot, so I didn't have to worry too much about the description in the seed file. While reading various things, I got the impression that the phrase "the array is taken out as a hash and the hash is taken out as an array to save the data" that came out in the official text was very easy to understand (remember).

I will leave it as a reminder.