मैंने सफलतापूर्वक एक डेटाबेस बनाया है और अपना पहला माइग्रेशन किया है:
class CreateUsers < ActiveRecord::Migration
def change
create_table :users do |t|
t.string :name
t.string :email
t.timestamps
end
end
end
जब मैं डेटाबेस प्राप्त करने की कोशिश करता हूं तो मुझे निम्नलिखित मिलते हैं:
rake aborted!
can"t convert nil into String
मैं इस समस्या का कारण हो सकता है या इसे कैसे डीबग करने के लिए अनिश्चित हूँ, इसलिए किसी भी मदद की सराहना की जाएगी।
मैं रेल 3.1 चला रहा हूं
त्रुटि का पूर्ण पता है:
** Invoke db:reset (first_time)
** Invoke db:drop (first_time)
** Invoke db:load_config (first_time)
** Invoke rails_env (first_time)
** Execute rails_env
** Execute db:load_config
** Execute db:drop
** Invoke db:setup (first_time)
** Invoke db:create (first_time)
** Invoke db:load_config
** Execute db:create
db/test.sqlite3 already exists
** Invoke db:schema:load (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute db:schema:load
-- create_table("users", {:force=>true})
-> 0.0050s
-- initialize_schema_migrations_table()
-> 0.0053s
-- assume_migrated_upto_version(20111212200427, ["/Users/xxxx/My_Work/Resources/Rails/Books/Rails-Tutorial/Sample-App/sample_app/db/migrate"])
-> 0.0055s
** Invoke db:seed (first_time)
** Invoke db:abort_if_pending_migrations (first_time)
** Invoke environment
** Execute db:abort_if_pending_migrations
** Execute db:seed
rake aborted!
can"t convert nil into String
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.1.0/lib/rails/engine.rb:487:in `exist?"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/railties-3.1.0/lib/rails/engine.rb:487:in `load_seed"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/activerecord-3.1.0/lib/active_record/railties/databases.rake:299:in `block (2 levels) in <top (required)>"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `call"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:205:in `block in execute"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `each"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:200:in `execute"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:158:in `block in invoke_with_call_chain"
/Users/xxxx/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:176:in `block in invoke_prerequisites"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:174:in `each"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:174:in `invoke_prerequisites"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:157:in `block in invoke_with_call_chain"
/Users/xxxx/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:176:in `block in invoke_prerequisites"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:174:in `each"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:174:in `invoke_prerequisites"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:157:in `block in invoke_with_call_chain"
/Users/xxxx/.rvm/rubies/ruby-1.9.3-p0/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:151:in `invoke_with_call_chain"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/task.rb:144:in `invoke"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:116:in `invoke_task"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block (2 levels) in top_level"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `each"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:94:in `block in top_level"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:88:in `top_level"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:66:in `block in run"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:133:in `standard_exception_handling"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/lib/rake/application.rb:63:in `run"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/gems/rake-0.9.2.2/bin/rake:33:in `<top (required)>"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/bin/rake:19:in `load"
/Users/xxxx/.rvm/gems/ruby-1.9.3-p0/bin/rake:19:in `<main>"
Tasks: TOP => db:reset => db:setup => db:seed
उत्तर:
उत्तर № 1 के लिए 1यह तलाश है db/seeds.rb, एक खाली करने से आपकी समस्या का समाधान होगा:
touch db/seeds.rb