Ruby Sinatra/Postgres - 无法使用 PG.connect 连接到 heroku 数据库？

Question

I am trying to get a site set up on Heroku using Sinatra and PostgreSQL. It worked locally (connecting to local database), but after pushing it to Heroku and changing my PG.connect to reflect that, I get an Internal Server Error the moment a page tries to access the database.

require 'uri'
require 'pg'

uri = URI.parse(ENV['DATABASE_URL'])

def db(uri)
  begin
    connection = PG.connect(uri.hostname, uri.port, nil, nil, uri.path[1..-1], uri.user, uri.password)
    yield(connection)
  ensure
    connection.close
  end
end

I am pretty sure these are parsing correctly, because ENV['DATABASE_URL'] displays the full postgres://user:password@host:port/database information that I'm expecting, and if I do the same in IRB uri.hostname, ui.port, etc all return what's expected .

This is my first time trying to get a site working on Heroku, so I am not even sure how to troubleshoot this. (And I googled for about all of yesterday.)

Results for heroku pg :

=== DATABASE_URL
Plan:        Hobby-dev
Status:      Available
Connections: 0/20
PG Version:  9.4.2
Created:     2015-05-30 19:24 UTC
Data Size:   17.7 MB
Tables:      5
Rows:        9320/10000 (In compliance, close to row limit)
Fork/Follow: Unsupported
Rollback:    Unsupported

And all the tables show up when when I do heroku pg:psql <database> from the cli.

Some answers I've seen said to add database.yml to my root app directory, so:

production:
  adapter: 'postgresql'
  database: '<database>'
  host: ENV['DATABASE_URL']
  username: '<username>'

There's probably something simple I'm missing, but I haven't seen a complete guide for Sinatra/PSQL on Heroku - nothing that goes specifically into setting up and connecting to your database. (Everything seems Rails-related.)

Answer 1

In your database.yml file you need to specify the correct host for the host entry. You are passing what is stored in DATABASE_URL (something like postgres://user:password@host:port/database ) but it should just be the host.

You will also need to specify a port if it isn't the default for PostgreSQL.

Edit: should also point out if you plan to store the host (or anything else - you definitely should for username and password) in an environment variable you'll need to wrap it, eg <%= ENV['HOST'] %> , not just ENV['HOST'] (ie how you have in the database.yml excerpt above)