質問: Couldn't create database for {"adapter"=>"mysql2", "encoding"=>"utf8", "pool"=>5, "username"=>"root", "password"=>nil, "host"=>"localhost", "database"=>"butelr_test"}, {:charset=>"utf8", :collation=>"utf8_unicode_ci"} (If you set the charset manually, make sure you have a matching collation)
回答: mysql起動させましょう、起動確認後にdatabase.yml眺めてみましょう。username, password, database間違っていないか。