Added SQL Server support

lib/geokit-rails/acts_as_mappable.rb

@@ -135,7 +135,9 @@ module SingletonMethods #:nodoc:
       def adapter
         @adapter ||= begin
           require File.join(File.dirname(__FILE__), 'adapters', connection.adapter_name.downcase)
-          Adapters.const_get(connection.adapter_name.camelcase).new(self)
+          klass = Adapters.const_get(connection.adapter_name.camelcase)
+          klass.load(self) unless klass.loaded
+          klass.new(self)
         rescue LoadError
           raise UnsupportedAdapter, "`#{connection.adapter_name.downcase}` is not a supported adapter."
         end

lib/geokit-rails/adapters/abstract.rb

@@ -3,6 +3,8 @@ module Adapters
     class Abstract
       class NotImplementedError < StandardError ; end
 
+      cattr_accessor :loaded
+
       def initialize(klass)
         @owner = klass
       end

lib/geokit-rails/adapters/sqlserver.rb

@@ -0,0 +1,43 @@
+module Geokit
+  module Adapters
+    class SQLServer < Abstract
+
+      class << self
+
+        def load(klass)
+          klass.connection.execute <<-EOS
+            if exists (select * from dbo.sysobjects where id = object_id(N'[dbo].[geokit_least]') and xtype in (N'FN', N'IF', N'TF'))
+            drop function [dbo].[geokit_least]
+          EOS
+
+          klass.connection.execute <<-EOS
+            CREATE FUNCTION [dbo].geokit_least (@value1 float,@value2 float) RETURNS float AS BEGIN
+            return (SELECT CASE WHEN @value1 < @value2 THEN  @value1 ELSE @value2 END) END
+          EOS
+          self.loaded = true
+        end
+
+      end
+
+      def initialize(*args)
+        super(*args)
+      end
+
+      def sphere_distance_sql(lat, lng, multiplier)
+        %|
+          (ACOS([dbo].geokit_least(1,COS(#{lat})*COS(#{lng})*COS(RADIANS(#{qualified_lat_column_name}))*COS(RADIANS(#{qualified_lng_column_name}))+
+          COS(#{lat})*SIN(#{lng})*COS(RADIANS(#{qualified_lat_column_name}))*SIN(RADIANS(#{qualified_lng_column_name}))+
+          SIN(#{lat})*SIN(RADIANS(#{qualified_lat_column_name}))))*#{multiplier})
+         |
+      end
+
+      def flat_distance_sql(origin, lat_degree_units, lng_degree_units)
+        %|
+          SQRT(POWER(#{lat_degree_units}*(#{origin.lat}-#{qualified_lat_column_name}),2)+
+          POWER(#{lng_degree_units}*(#{origin.lng}-#{qualified_lng_column_name}),2))
+         |
+      end
+
+    end
+  end
+end

test/database.yml

@@ -2,7 +2,7 @@ baes: &base
   host: localhost
   username: root
   password: 
-  
+
 mysql:
   adapter: mysql
   database: geokit_plugin_test
@@ -11,4 +11,10 @@ mysql:
 postgresql:
   adapter: postgresql
   database: geokit_plugin_test
-  <<: *base
+  <<: *base
+
+sqlserver:
+  adapter: sqlserver
+  mode: ODBC
+  dsn: geokit_tests
+  username: ruby