如何在Heroku中为Sinatra应用程序设置数据库？

Question

I made a Sinatra application that runs with a SQLite3 database. Everything runs smoothly on my local machine.

When I am deployed it to Heroku I had to change a few things, namely a Gemfile and a Procfile, while also changing my database code to this:

#Within a class

#Before
@DB = Sequel.connect('sqlite://database.db')

#After
@DB = Sequel.connect(ENV['DATABASE_URL'] || 'postgres://localhost/db')

I changeed the database to Postgres, rather than SQLite3 because SQLite3 isn't supported with Heroku. (This may be where my problem stems from.)

Here is my Gemfile:

source "https://rubygems.org"
ruby "1.9.3"

gem "sinatra"
gem "sequel"
gem "pg"
gem "postgres"
gem "json"

And my Procfile:

web: bundle exec ruby main.rb -p $PORT

---

I made a git repository, and ran heroku create . I added all the files, committed and pushed them using git and I got my Heroku URL and everything is fine. I ran heroku config to check my URLs and got this result:

DATABASE_URL:postgres://uhyodailuzazve:hUSIuD_4MOYWmoiSGNZCPrQNyg@ec2-54-204-40-     140.compute-1.amazonaws.com:5432/d1qkn1ivl7p013HEROKU_POSTGRESQL_BLACK_URL:postgres://uhyodailuzazve:hUSIuD_4MOYWmoiSGNZCPrQNyg@ec2-54-204-40-140.compute-1.amazonaws.com:5432/d1qkn1ivl7p013

(They are the same). Also my stack is "cedar"

=== enigmatic-taiga-5020 Available Stacks
bamboo-mri-1.9.2
bamboo-ree-1.8.7
* cedar

How can I have a database configured with Sinatra, going from Sequel to Postgres? I've looked at tutorials and they have gotten this far. Has anyone done this before?

Answer 1

@DB = Sequel.connect(ENV['DATABASE_URL'])应该可以正常工作，尽管通常您会将数据库分配给常量，而不是实例变量。