顺手吃个瓜，帮 ruby china 增加下活跃度，坚挺是很坚挺，但活跃度肯定比掘金和 sf 差很多。

有些标签是用户和文章公用的，例如：技术，ruby，但有些标签仅可以用于文章，如：通俗易懂等等，可能 tag 表还需要加一个分类...

1 月 9 号，京东还没发货，悲伤

这种写法和在 if 语句中赋值一样，非常容易产生误解，万一产生 bug，要排查好久，最关键的是会坑后来读代码的人。

不要追求代码的简短，要追求可读性。

这不是楼主说的脚本语言吧。

能胜任。 事实上一个领域流行某种语言和语言特性关系不大，主要看该领域最初的开拓者擅长或者喜欢哪种语言，开拓者定了方向，后续的人都只是跟进。

这个和科学里面的单起源说和多起源说有一定的关系，越小的领域，单起源性可能越高，金融，科学计算都算，越大的领域，多起源的可能性就越高，例如 web，app。

虽然现在没有太多机会，但是随着科学计算的领域扩大和门槛的降低，将来还是有一定可能的，前提是 ruby 要能够维持住足够多的开发者，尤其是顶端开发者。

还好，凡事讲相对而言，相比于其他论坛，这里的和谐度仅次于 2048。

说实话，你这样会显的素质比较低。

大家一般会觉得做 ruby 的人本来数量就不多，素质还不咋地。

#6 楼 @lilonglongRoR 版本是 20141027 这种在文件前的数组吗？ 这样就等同于一次执行一个文件了。

#3 楼 @paul_king 删了下，还是一样的

#4 楼 @ailen 也没有用

我还是写一个文件执行一下 rake db:migrate 吧，这样就没问题。

#1 楼 @ailen

[root@luoyou1014 teach]# rake db:migrate
== 20141022053115 CreateUsers: migrating ======================================
-- create_table(:users)
   -> 0.0044s
== 20141022053115 CreateUsers: migrated (0.0045s) =============================

== 20141022053301 CreateCourseTags: migrating =================================
-- create_table(:course_tags)
   -> 0.0004s
== 20141022053301 CreateCourseTags: migrated (0.0004s) ========================

rake aborted!
StandardError: An error has occurred, this and all later migrations canceled:

SQLite3::SQLException: database schema has changed: INSERT INTO "schema_migrations" ("version") VALUES (?)/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:108:in `step'
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:108:in `block in each'
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:107:in `loop'
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:107:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:319:in `to_a'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:319:in `block in exec_query'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract_adapter.rb:373:in `block in log'
/usr/local/rvm/gems/ruby-2.1.3/gems/activesupport-4.1.6/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract_adapter.rb:367:in `log'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:298:in `exec_query'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:68:in `exec_insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:95:in `insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/query_cache.rb:14:in `insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/relation.rb:64:in `insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/persistence.rb:503:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/attribute_methods/dirty.rb:87:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:306:in `block in _create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activesupport-4.1.6/lib/active_support/callbacks.rb:82:in `run_callbacks'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:306:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/timestamp.rb:57:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/persistence.rb:483:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:302:in `block in create_or_update'
/usr/local/rvm/gems/ruby-2.1.3/gems/activesupport-4.1.6/lib/active_support/callbacks.rb:82:in `run_callbacks'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:302:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/persistence.rb:125:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/validations.rb:57:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/attribute_methods/dirty.rb:29:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:273:in `block in save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:329:in `block in with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:199:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:208:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:326:in `with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:273:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/validations.rb:41:in `create!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:1022:in `record_version_state_after_migrating'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:992:in `block in execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:1037:in `block in ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `block in transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:209:in `within_new_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:208:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:1037:in `ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:990:in `execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:952:in `block in migrate'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:948:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:948:in `migrate'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:807:in `up'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:785:in `migrate'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/railties/databases.rake:34:in `block (2 levels) in <top (required)>'
ActiveRecord::StatementInvalid: SQLite3::SQLException: database schema has changed: INSERT INTO "schema_migrations" ("version") VALUES (?)
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:108:in `step'
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:108:in `block in each'
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:107:in `loop'
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:107:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:319:in `to_a'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:319:in `block in exec_query'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract_adapter.rb:373:in `block in log'
/usr/local/rvm/gems/ruby-2.1.3/gems/activesupport-4.1.6/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract_adapter.rb:367:in `log'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:298:in `exec_query'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:68:in `exec_insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:95:in `insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/query_cache.rb:14:in `insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/relation.rb:64:in `insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/persistence.rb:503:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/attribute_methods/dirty.rb:87:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:306:in `block in _create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activesupport-4.1.6/lib/active_support/callbacks.rb:82:in `run_callbacks'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:306:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/timestamp.rb:57:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/persistence.rb:483:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:302:in `block in create_or_update'
/usr/local/rvm/gems/ruby-2.1.3/gems/activesupport-4.1.6/lib/active_support/callbacks.rb:82:in `run_callbacks'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:302:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/persistence.rb:125:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/validations.rb:57:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/attribute_methods/dirty.rb:29:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:273:in `block in save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:329:in `block in with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:199:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:208:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:326:in `with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:273:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/validations.rb:41:in `create!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:1022:in `record_version_state_after_migrating'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:992:in `block in execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:1037:in `block in ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `block in transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:209:in `within_new_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:208:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:1037:in `ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:990:in `execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:952:in `block in migrate'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:948:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:948:in `migrate'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:807:in `up'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:785:in `migrate'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/railties/databases.rake:34:in `block (2 levels) in <top (required)>'
SQLite3::SQLException: database schema has changed
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:108:in `step'
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:108:in `block in each'
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:107:in `loop'
/usr/local/rvm/gems/ruby-2.1.3/gems/sqlite3-1.3.9/lib/sqlite3/statement.rb:107:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:319:in `to_a'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:319:in `block in exec_query'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract_adapter.rb:373:in `block in log'
/usr/local/rvm/gems/ruby-2.1.3/gems/activesupport-4.1.6/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract_adapter.rb:367:in `log'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/sqlite3_adapter.rb:298:in `exec_query'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:68:in `exec_insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:95:in `insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/query_cache.rb:14:in `insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/relation.rb:64:in `insert'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/persistence.rb:503:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/attribute_methods/dirty.rb:87:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:306:in `block in _create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activesupport-4.1.6/lib/active_support/callbacks.rb:82:in `run_callbacks'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:306:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/timestamp.rb:57:in `_create_record'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/persistence.rb:483:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:302:in `block in create_or_update'
/usr/local/rvm/gems/ruby-2.1.3/gems/activesupport-4.1.6/lib/active_support/callbacks.rb:82:in `run_callbacks'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/callbacks.rb:302:in `create_or_update'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/persistence.rb:125:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/validations.rb:57:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/attribute_methods/dirty.rb:29:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:273:in `block in save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:329:in `block in with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:199:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:208:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:326:in `with_transaction_returning_status'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:273:in `save!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/validations.rb:41:in `create!'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:1022:in `record_version_state_after_migrating'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:992:in `block in execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:1037:in `block in ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `block in transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:209:in `within_new_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/connection_adapters/abstract/database_statements.rb:201:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/transactions.rb:208:in `transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:1037:in `ddl_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:990:in `execute_migration_in_transaction'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:952:in `block in migrate'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:948:in `each'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:948:in `migrate'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:807:in `up'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/migration.rb:785:in `migrate'
/usr/local/rvm/gems/ruby-2.1.3/gems/activerecord-4.1.6/lib/active_record/railties/databases.rake:34:in `block (2 levels) in <top (required)>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)