could not find table subjects disable_ddl_transaction rails 3

I am new to ruby I was trying ruby by looking into tutorialpoints.com

whiile migrating m getting this error

C:\Users\Anit\Documents\ruby\library>rake db:migrate
rake aborted!
ActiveRecord::StatementInvalid: Could not find table 'subjects'
C:in `disable_ddl_transaction'
ActiveRecord::StatementInvalid: Could not find table 'subjects'
C:in `disable_ddl_transaction'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

After running with --trace

C:\Users\Anit\Documents\ruby\library>rake db:migrate --trace
** Invoke db:migrate (first_time)
** Invoke environment (first_time)
** Execute environment
** Invoke db:load_config (first_time)
** Execute db:load_config
** Execute db:migrate
rake aborted!
ActiveRecord::StatementInvalid: Could not find table 'subjects'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:513:in `table_structure'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:387:in `columns'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/schema_cache.rb:43:in `columns'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/attributes.rb:93:in `columns'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/attributes.rb:98:in `columns_hash'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/inheritance.rb:205:in `subclass_from_attributes?'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/inheritance.rb:54:in `new'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:778:in `load_migration'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:773:in `migration'
C:in `disable_ddl_transaction'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:1051:in `use_transaction?'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:961:in `rescue in block in migrate'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:958:in `block in migrate'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:955:in `each'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:955:in `migrate'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:823:in `up'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:801:in `migrate'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/tasks/database_tasks.rb:137:in `migrate'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/railties/databases.rake:44:in `block (2 levels) in '
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:248:in `call'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:248:in `block in execute'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:243:in `each'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:243:in `execute'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:187:in `block in invoke_with_call_chain'
C:/Ruby22-x64/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:180:in `invoke_with_call_chain'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:173:in `invoke'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:150:in `invoke_task'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:106:in `each'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:106:in `block in top_level'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:115:in `run_with_threads'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:100:in `top_level'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:78:in `block in run'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:176:in `standard_exception_handling'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:75:in `run'
C:/Ruby22-x64/bin/rake:33:in `'
ActiveRecord::StatementInvalid: Could not find table 'subjects'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:513:in `table_structure'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:387:in `columns'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/connection_adapters/schema_cache.rb:43:in `columns'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/attributes.rb:93:in `columns'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/attributes.rb:98:in `columns_hash'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/inheritance.rb:205:in `subclass_from_attributes?'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/inheritance.rb:54:in `new'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:778:in `load_migration'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:773:in `migration'
C:in `disable_ddl_transaction'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:1051:in `use_transaction?'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:1043:in `ddl_transaction'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:997:in `execute_migration_in_transaction'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:959:in `block in migrate'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:955:in `each'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:955:in `migrate'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:823:in `up'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/migration.rb:801:in `migrate'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/tasks/database_tasks.rb:137:in `migrate'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/activerecord-4.2.6/lib/active_record/railties/databases.rake:44:in `block (2 levels) in '
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:248:in `call'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:248:in `block in execute'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:243:in `each'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:243:in `execute'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:187:in `block in invoke_with_call_chain'
C:/Ruby22-x64/lib/ruby/2.2.0/monitor.rb:211:in `mon_synchronize'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:180:in `invoke_with_call_chain'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/task.rb:173:in `invoke'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:150:in `invoke_task'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:106:in `block (2 levels) in top_level'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:106:in `each'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:106:in `block in top_level'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:115:in `run_with_threads'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:100:in `top_level'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:78:in `block in run'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:176:in `standard_exception_handling'
C:/Ruby22-x64/lib/ruby/gems/2.2.0/gems/rake-11.1.2/lib/rake/application.rb:75:in `run'
C:/Ruby22-x64/bin/rake:33:in `'
Tasks: TOP => db:migrate