heroku db:pull postgresql://root:@localhost/db_name
After this command display this message
/usr/lib/ruby/gems/1.8/gems/rest-client-1.6.1/lib/restclient/abstract_response.rb:50: warning: parenthesize argument(s) for future version Loaded Taps v0.3.13 Warning: Data in the database 'postgresql://root:@localhost/db_name' will be overwritten and will not be recoverable. Are you sure you wish to continue? (y/n)? y Failed to connect to database: Sequel::AdapterNotFound -> LoadError: no such file to load -- sequel/adapters/postgresql
How to use db:pull
First, you need to fix your connection string: use postgres instead of postgresql.
You will need to have the pg db adapter installed to use Sequel's postgresql adapter:
gem install pg
You may also want to make sure your taps, sequel, and heroku gems are up to date:
gem install heroku taps sequel
Then try your heroku db:pull again. If that doesn't work, post a comment or hop in #heroku on Freenode and we can try to help.
Your connection string is wrong. Try:
heroku db:pull postgres://root:@localhost/db_name
Started working fine once I upgraded the "pg" gem from version "0.11.0" to "0.12.2".
来源：https://stackoverflow.com/questions/3841237/heroku-dbpull-not-working