带有新Rails应用程序的现有数据库

Question

我在flask使用了一个存在于postgresql名为exam_prep数据库。

我已经创建了一个新的Rails应用程序，并且希望将其与该数据库一起使用。

到目前为止，我已经运行rake db:structure:dump ，它在db文件夹下创建了一个structure.sql 。

之后，我运行了db:structure:load ，但收到以下错误：

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使用数据库并在其中建立模型。 有任何想法吗？

Answer 1

db:structure:load rake任务从structure.sql或schema.rb创建表和列。 您不需要运行它，因为现有数据库已经具有所需的所有表。

下一步将是创建模型文件并将它们指向适当的表。