我已经用谷歌搜索并搜索了这个问题的答案，所以即使这个问题与已经提出的其他问题相似，请知道我已经尝试了这里发布的所有答案。
我一直在关注一个教程来建立一个包含用户等的 Rails 站点。我正处于尝试使用 Devise 生成用户数据库的阶段。
当我尝试访问注册页面时出现此错误：
ActiveRecord::StatementInvalid in Devise::RegistrationsController#new
我发现的建议是rake db:migrate用来修复数据库。
这给了我以下错误：
SQLite3::SQLException: duplicate column name: email: ALTER TABLE "installs" ADD "email" varchar(255) DEFAULT '' NOT NULL/ruby/testapp/omrails/db/migrate/20130510151217_add_devise_to_installs.rb:5:in `block in up'
/ruby/testapp/omrails/db/migrate/20130510151217_add_devise_to_installs.rb:3:in `up'
/Users/BWS/.rvm/gems/ruby-1.9.3-p392/bin/ruby_noexec_wrapper:14:in `eval'
/Users/BWS/.rvm/gems/ruby-1.9.3-p392/bin/ruby_noexec_wrapper:14:in `<main>'
Tasks: TOP => db:migrate
然后，互联网使我相信删除我的 development.sqlite3 并重新运行rake db:migrate将解决我的问题，但这会导致：
SQLite3::SQLException: duplicate column name: email: ALTER TABLE "installs" ADD "email" varchar(255) DEFAULT '' NOT NULL/ruby/testapp/omrails/db/migrate/20130510151217_add_devise_to_installs.rb:5:in `block in up'
再次。
[可能相关] 当我使用 rails 做任何事情时，我也会收到以下消息：
/Users/BWS/.rvm/rubies/ruby-1.9.3-p392/lib/ruby/1.9.1/yaml.rb:56:in `<top (required)>':
It seems your ruby installation is missing psych (for YAML output).
To eliminate this warning, please install libyaml and reinstall your ruby.
但是所有在线建议的建议都还没有解决这个问题。
很抱歉，这篇文章很长，试图非常彻底，任何建议都将不胜感激。
更新：
所以我不能让它生成一个新的模式（我多次删除 DB 文件夹以尝试不同的东西）但这是已删除的模式之一：
# encoding: UTF-8
# This file is auto-generated from the current state of the database. Instead
# of editing this file, please use the migrations feature of Active Record to
# incrementally modify your database, and then regenerate this schema definition.
#
# Note that this schema.rb definition is the authoritative source for your
# database schema. If you need to create the application database on another
# system, you should be using db:schema:load, not running all the migrations
# from scratch. The latter is a flawed and unsustainable approach (the more migrations
# you'll amass, the slower it'll run and the greater likelihood for issues).
#
# It's strongly recommended to check this file into your version control system.
ActiveRecord::Schema.define(:version => 0) do
end