帶有新Rails應用程序的現有數據庫

Question

我在flask使用了一個存在於postgresql名為exam_prep數據庫。

我已經創建了一個新的Rails應用程序，並且希望將其與該數據庫一起使用。

到目前為止，我已經運行rake db:structure:dump ，它在db文件夾下創建了一個structure.sql 。

之后，我運行了db:structure:load ，但收到以下錯誤：

psql:/Users/namangupta/Desktop/app/db/structure.sql:49: ERROR:  type "batch_types_enum" already exists
rake aborted!
failed to execute:
psql -v ON_ERROR_STOP=1 -q -f /Users/namangupta/Desktop/app/db/structure.sql exam_prep

Please check the output above for any errors and make sure that `psql` is installed in your PATH and has proper permissions.

/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:108:in `run_cmd'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/tasks/postgresql_database_tasks.rb:80:in `structure_load'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:223:in `structure_load'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:236:in `load_schema'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:255:in `block in load_schema_current'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:304:in `block in each_current_configuration'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:303:in `each'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:303:in `each_current_configuration'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/tasks/database_tasks.rb:254:in `load_schema_current'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/activerecord-5.1.4/lib/active_record/railties/databases.rake:290:in `block (3 levels) in <top (required)>'
/Users/namangupta/.rvm/gems/ruby-2.3.4/gems/rake-12.3.0/exe/rake:27:in `<top (required)>'
/Users/namangupta/.rvm/gems/ruby-2.3.4/bin/ruby_executable_hooks:15:in `eval'
/Users/namangupta/.rvm/gems/ruby-2.3.4/bin/ruby_executable_hooks:15:in `<main>'
Tasks: TOP => db:structure:load
(See full trace by running task with --trace)

我希望Rails使用數據庫並在其中建立模型。 有任何想法嗎？

Answer 1

db:structure:load rake任務從structure.sql或schema.rb創建表和列。 您不需要運行它，因為現有數據庫已經具有所需的所有表。

下一步將是創建模型文件並將它們指向適當的表。