Index: Gemfile
===================================================================
--- Gemfile	(revision 11168)
+++ Gemfile	(working copy)
@@ -28,45 +28,37 @@
   end
 end
 
-# Database gems
-platforms :mri, :mingw do
-  group :postgresql do
-    gem "pg", ">= 0.11.0"
-  end
-
-  group :sqlite do
-    gem "sqlite3"
-  end
-end
-
-platforms :mri_18, :mingw_18 do
-  group :mysql do
-    gem "mysql", "~> 2.8.1"
-  end
-end
-
-platforms :mri_19, :mingw_19 do
-  group :mysql do
-    gem "mysql2", "~> 0.3.11"
-  end
-end
-
 platforms :jruby do
   # jruby-openssl is bundled with JRuby 1.7.0
   gem "jruby-openssl" if Object.const_defined?(:JRUBY_VERSION) && JRUBY_VERSION < '1.7.0'
   gem "activerecord-jdbc-adapter", "1.2.5"
-
-  group :mysql do
-    gem "activerecord-jdbcmysql-adapter"
-  end
-
-  group :postgresql do
-    gem "activerecord-jdbcpostgresql-adapter"
-  end
+end
 
-  group :sqlite do
-    gem "activerecord-jdbcsqlite3-adapter"
+database_file = File.join(File.dirname(__FILE__), "config/database.yml")
+if File.exist?(database_file)
+  database_config = YAML.load_file(database_file)
+  adapters = database_config.values.map {|c| c['adapter']}.uniq
+  adapters.each do |adapter|
+    case adapter
+    when /mysql/
+      gem "mysql", "~> 2.8.1", :platforms => [:mri_18, :mingw_18]
+      gem "mysql2", "~> 0.3.11", :platforms => [:mri_19, :mingw_19]
+      gem "activerecord-jdbcmysql-adapter", :platforms => :jruby
+    when /postgresql/
+      gem "pg", ">= 0.11.0", :platforms => [:mri, :mingw]
+      gem "activerecord-jdbcpostgresql-adapter", :platforms => :jruby
+    when /sqlite3/
+      gem "sqlite3", :platforms => [:mri, :mingw]
+      gem "activerecord-jdbcsqlite3-adapter", :platforms => :jruby
+    when /sqlserver/
+      gem "tiny_tds", :platforms => [:mri, :mingw]
+      gem "activerecord-sqlserver-adapter", :platforms => [:mri, :mingw]
+    else
+      abort("Unknown database adapter `#{adapter}` found in database.yml")
+    end
   end
+else
+  abort("Please, configure your database.yml first")
 end
 
 group :development do