我是 Rails 新手，我正在尝试执行 rake db:schema:dump，但我遇到了这个问题。
rake db:schema:dump --trace
** Invoke db:schema:dump (first_time)
** Invoke environment (first_time)
** Execute environment
** Invoke db:load_config (first_time)
** Execute db:load_config
** Execute db:schema:dump
rake aborted!
Can't connect to local MySQL server through socket '/tmp/mysql.sock' (111)
/var/lib/gems/1.9.1/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `connect'
/var/lib/gems/1.9.1/gems/mysql2-0.3.11/lib/mysql2/client.rb:44:in `initialize'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `new'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/mysql2_adapter.rb:16:in `mysql2_connection
'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:315:in `new_co
nnection'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:325:in `checko
ut_new_connection'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:247:in `block
(2 levels) in checkout'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `loop'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:242:in `block
in checkout'
/usr/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:239:in `checko
ut'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:102:in `block
in connection'
/usr/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:101:in `connec
tion'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_pool.rb:410:in `retrie
ve_connection'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_specification.rb:171:i
n `retrieve_connection'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/connection_adapters/abstract/connection_specification.rb:145:i
n `connection'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/railties/databases.rake:379:in `block (4 levels) in <top (requ
ired)>'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/railties/databases.rake:378:in `open'
/var/lib/gems/1.9.1/gems/activerecord-3.2.9/lib/active_record/railties/databases.rake:378:in `block (3 levels) in <top (requ
ired)>'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:228:in `call'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:228:in `block in execute'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:223:in `each'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:223:in `execute'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:166:in `block in invoke_with_call_chain'
/usr/lib/ruby/1.9.1/monitor.rb:211:in `mon_synchronize'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:159:in `invoke_with_call_chain'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/task.rb:152:in `invoke'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:143:in `invoke_task'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:101:in `block (2 levels) in top_level'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:101:in `each'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:101:in `block in top_level'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:110:in `run_with_threads'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:95:in `top_level'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:73:in `block in run'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:160:in `standard_exception_handling'
/var/lib/gems/1.9.1/gems/rake-10.0.3/lib/rake/application.rb:70:in `run'
/var/lib/gems/1.9.1/gems/rake-10.0.3/bin/rake:33:in `<top (required)>'
/usr/local/bin/rake:23:in `load'
/usr/local/bin/rake:23:in `<main>'
Tasks: TOP => db:schema:dump
我已经创建了数据库，当我尝试连接时遇到了这个问题。
我的 database.yml 是：
# SQLite version 3.x
# gem install sqlite3
#
# Ensure the SQLite 3 gem is defined in your Gemfile
# gem 'sqlite3'
# development:
# adapter: sqlite3
# database: db/development.sqlite3
# pool: 5
# timeout: 5000
development:
adapter: mysql2
encoding: utf8
reconnect: false
database: simple_cms_develoment
pool: 5
username: simple_cms
password: secretpassword
socket: /tmp/mysql.sock
# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
adapter: sqlite3
database: db/test.sqlite3
pool: 5
timeout: 5000
production:
adapter: sqlite3
database: db/production.sqlite3
pool: 5
timeout: 5000
我的gemfile是：
source 'https://rubygems.org'
gem 'rails', '3.2.9'
# Bundle edge Rails instead:
# gem 'rails', :git => 'git://github.com/rails/rails.git'
gem 'mysql2'
gem 'activerecord-mysql-adapter'
gem 'bootstrap-sass'
# Gems used only for assets and not required
# in production environments by default.
group :assets do
gem 'sass-rails', '~> 3.2.3'
gem 'coffee-rails', '~> 3.2.1'
# See https://github.com/sstephenson/execjs#readme for more supported runtimes
# gem 'therubyracer', :platforms => :ruby
gem 'uglifier', '>= 1.0.3'
end
gem 'jquery-rails'
# To use ActiveModel has_secure_password
# gem 'bcrypt-ruby', '~> 3.0.0'
# To use Jbuilder templates for JSON
# gem 'jbuilder'
# Use unicorn as the app server
# gem 'unicorn'
# Deploy with Capistrano
# gem 'capistrano'
# To use debugger
# gem 'debugger'
谁能帮我？