1 files changed, 14 insertions, 1 deletions
diff --git a/activerecord/lib/active_record/railtie.rb b/activerecord/lib/active_record/railtie.rb
index ff98c829f4..2c796f97e6 100644
--- a/activerecord/lib/active_record/railtie.rb
+++ b/activerecord/lib/active_record/railtie.rb
@@ -43,11 +43,24 @@ module ActiveRecord
       namespace :db do
         task :load_config do
           ActiveRecord::Tasks::DatabaseTasks.db_dir = Rails.application.config.paths["db"].first
-          ActiveRecord::Tasks::DatabaseTasks.database_configuration = Rails.application.config.database_configuration
           ActiveRecord::Tasks::DatabaseTasks.migrations_paths = Rails.application.paths['db/migrate'].to_a
           ActiveRecord::Tasks::DatabaseTasks.fixtures_path = File.join Rails.root, 'test', 'fixtures'
           ActiveRecord::Tasks::DatabaseTasks.root = Rails.root
 
+          configuration = if ENV["DATABASE_URL"]
+            { Rails.env => ENV["DATABASE_URL"] }
+          else
+            Rails.application.config.database_configuration || {}
+          end
+
+          resolver = ActiveRecord::ConnectionAdapters::ConnectionSpecification::Resolver.new(configuration)
+
+          configuration.each do |key, value|
+            configuration[key] = resolver.resolve(value) if value
+          end
+
+          ActiveRecord::Tasks::DatabaseTasks.database_configuration = configuration
+
           if defined?(ENGINE_PATH) && engine = Rails::Engine.find(ENGINE_PATH)
             if engine.paths['db/migrate'].existent
               ActiveRecord::Tasks::DatabaseTasks.migrations_paths += engine.paths['db/migrate'].to_a