rake db：migrate的迁移错误

Question

我创建了一个新模型，但是当我运行rake db: migrate命令时，它会向我发出以下错误：

rake aborted!
Gem::LoadError: You have already activated rake 10.4.0, but your Gemfile requires rake 
10.3.2. Prepending `bundle exec` to your command may solve this.
/Users/yedidyaweiner/projects/music-app/config/boot.rb:4:in `<top (required)>'
/Users/yedidyaweiner/projects/music-app/config/application.rb:1:in `<top (required)>'
/Users/yedidyaweiner/projects/music-app/Rakefile:4:in `<top (required)>'
LoadError: cannot load such file -- bundler/setup
/Users/yedidyaweiner/projects/music-app/config/boot.rb:4:in `<top (required)>'
/Users/yedidyaweiner/projects/music-app/config/application.rb:1:in `<top (required)>'
 /Users/yedidyaweiner/projects/music-app/Rakefile:4:in `<top (required)>'

(See full trace by running task with --trace)

我究竟做错了什么？

Answer 1

采用

bundle exec rake db:migrate

Answer 2

您还可以通过运行更新您的宝石

bundle update

Answer 3

执行以下命令

a）删除您的Gemfile.lock文件

b）捆绑安装

它应该使用正确的rake更新Gemfile.lock。

要么

a）gem uninstall rake -v 10.4.0

b）gem install rake -v 10.3.2

---

然后尝试运行'rake db：migrate'。 它应该工作。