From 20bb694d4cc891619e312c2441a8995b7dbe215f Mon Sep 17 00:00:00 2001
From: Brennan Dunn <me@brennandunn.com>
Date: Tue, 29 Sep 2009 15:09:54 -0400
Subject: [PATCH] Added SQL Server support

---
 lib/geokit-rails/acts_as_mappable.rb   |  4 ++-
 lib/geokit-rails/adapters/abstract.rb  |  2 ++
 lib/geokit-rails/adapters/sqlserver.rb | 43 ++++++++++++++++++++++++++
 test/database.yml                      | 10 ++++--
 4 files changed, 56 insertions(+), 3 deletions(-)
 create mode 100644 lib/geokit-rails/adapters/sqlserver.rb

diff --git a/lib/geokit-rails/acts_as_mappable.rb b/lib/geokit-rails/acts_as_mappable.rb
index 9a73b88..e80dcb5 100644
--- a/lib/geokit-rails/acts_as_mappable.rb
+++ b/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
diff --git a/lib/geokit-rails/adapters/abstract.rb b/lib/geokit-rails/adapters/abstract.rb
index f7df2ee..7d98816 100644
--- a/lib/geokit-rails/adapters/abstract.rb
+++ b/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
diff --git a/lib/geokit-rails/adapters/sqlserver.rb b/lib/geokit-rails/adapters/sqlserver.rb
new file mode 100644
index 0000000..b1aea20
--- /dev/null
+++ b/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
\ No newline at end of file
diff --git a/test/database.yml b/test/database.yml
index d1af3ae..6851d14 100644
--- a/test/database.yml
+++ b/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
\ No newline at end of file
+  <<: *base
+
+sqlserver:
+  adapter: sqlserver
+  mode: ODBC
+  dsn: geokit_tests
+  username: ruby