Rails是否为每个应用程序创建单独的数据库

Question

I am a beginner in Rails, trying some examples on my Windows 7 machine.

I am getting the following error : SQLite3::SQLException: table "entries" already exists

"entries" is a table that was already created in another Rails application, and I am trying a similar example that is trying to create "entries" again.

Does Rails create a separate database in sqlite for each application ? (I am new to Sqlite also).

Answer 1

By default, when using sqlite, Rails uses databases named development.sqlite3 , test.sqlite3 , production.sqlite3 which are files in the db directory of the Rails project.

So you'll end up using the same database if your new application is in the same folder as your old one; or if your config/database.yml file is pointing to some common location for the DBs.

Answer 2

For each application there is a database.yml file in config folder of your application. You can define your database name unique to your application together with your database settings. Probably you just have the same database.yml file for both of your projects. So your current application is also trying to create the table which is already existed(created by database.yml file of your previous application).

The solution is to change the database.yml specific to your application.

After that you can run:

rake db:create

rake db:migrate

in the above order and it will be all fine.

You can also do only rake db:drop and then the above two commands without modifying your any database.yml file but this will delete your previous database and create the new one for this application fresh. But this is not recommended.