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[英]Why exactly does schema.rb get modified if I run `rake db:migrate` immediately after `rake db:schema:load`?
[英]Rake db:setup does not run rails db:migrate, schema.rb does not exist error
在 Rails 6 上,我希望rake db:setup
執行db:create
、 db:migrate
和db:seed
我只有一個數據模型,其表的記錄創建是在db/seeds.rb
# db/seeds.rb
require 'csv'
csv_text = File.read(Rails.root.join('lib', 'seeds', 'seed_first_table.csv'))
csv = CSV.parse(csv_text, :headers => true, :encoding => 'ISO-8859-1')
csv.each_with_index do |row, index|
cr = CatProfile.new
puts "row #{index} saved"
end
puts "There are now #{CatProfile.count} rows in the table"
database.yml
還有一個新的用戶憑證,它是通過sudo -u postgres createuser -s new_user
但是rake db:setup
返回:
Created database 'my_application_development'
Created database 'my_application_test'
my_application/db/schema.rb doesn't exist yet. Run `rails db:migrate` to create it, then try again. If you do not intend to use a database, you should instead alter /my_application/config/application.rb to limit the frameworks that will be loaded.
在sudo -u postgres psql
它確實創建了數據庫,但沒有關系(沒有種子表)
當我運行rails db:migrate
== 20201103153526 CreateCatProfiles: migrating =================================
-- create_table(:cat_profiles)
-> 0.0091s
== 20201103153526 CreateCatProfiles: migrated (0.0092s) ========================
然后當我第二次運行rake db:setup
時:
Database 'my_application_development' already exists
Database 'my_application_test' already exists
row 0 saved
row 1 saved
...
row 1719 saved
There are now 1720 rows in the table
注意到數據庫已經從第一個rake db:setup
存在,但現在它能夠為表做種子
我不明白為什么第一次運行rake db:setup
沒有在播種前進行必要的遷移
如果您查看rails db:setup
的源代碼,您將看到db:setup
不運行db:migrate
創建數據庫,加載模式,並用種子數據初始化(使用 db:reset 也首先刪除數據庫)
db:schema:load
將schema.rb
當前存在的內容加載到數據庫中。
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