Support newer version of DBI/ODBC. Tested with DBI 0.4.0 and DBD::ODBC 0.2.4 via gem install. Biggest bugs were to fix the #column_definitions method to not have DBI cast values for column_info which was very buggy. Also added a few DBI::Type classes for custom parsing like datetime.

Author: metaskills

lib/active_record/connection_adapters/sqlserver_adapter.rb

@@ -610,6 +610,13 @@ def raw_execute(sql, name = nil, &block)
         end
       end
 
+      def without_type_conversion
+        raw_connection.convert_types = false if raw_connection.respond_to?(:convert_types=)
+        yield
+      ensure
+        raw_connection.convert_types = true if raw_connection.respond_to?(:convert_types=)
+      end
+      
       def do_execute(sql,name=nil)
         log(sql, name || 'EXECUTE') do
           raw_connection.do(sql)
@@ -622,6 +629,7 @@ def raw_select(sql, name = nil)
         results = handle_as_array(handle)
         rows = results.inject([]) do |rows,row|
           row.each_with_index do |value, i|
+            # DEPRECATED in DBI 0.4.0 and above. Remove when 0.2.2 and lower is no longer supported.
             if value.is_a? DBI::Timestamp
               row[i] = value.to_sqlserver_string
             end
@@ -802,7 +810,7 @@ def column_definitions(table_name)
           WHERE columns.TABLE_NAME = '#{table_name}'
           ORDER BY columns.ordinal_position
         }.gsub(/[ \t\r\n]+/,' ')
-        results = select(sql,nil,true)
+        results = without_type_conversion { select(sql,nil,true) }
         results.collect do |ci|
           ci.symbolize_keys!
           ci[:type] = if ci[:type] =~ /numeric|decimal/i
@@ -811,7 +819,7 @@ def column_definitions(table_name)
                         "#{ci[:type]}(#{ci[:length]})"
                       end
           ci[:default_value] = ci[:default_value].match(/\A\(+N?'?(.*?)'?\)+\Z/)[1] if ci[:default_value]
-          ci[:null] = ci[:is_nullable] == 1 ; ci.delete(:is_nullable)
+          ci[:null] = ci[:is_nullable].to_i == 1 ; ci.delete(:is_nullable)
           ci
         end
       end

lib/core_ext/dbi.rb

@@ -1,17 +1,83 @@
+
 module SQLServerDBI
+  
   module Timestamp
-    
-    # Will further change DBI's #to_s return value by limiting the usec of the time 
-    # to 3 digits and in some cases adding zeros if needed. For example:
+    # Will further change DBI::Timestamp #to_s return value by limiting the usec of 
+    # the time to 3 digits and in some cases adding zeros if needed. For example:
     #   "1985-04-15 00:00:00.0"         # => "1985-04-15 00:00:00.000"
     #   "2008-11-08 10:24:36.547000"    # => "2008-11-08 10:24:36.547"
     #   "2008-11-08 10:24:36.123"       # => "2008-11-08 10:24:36.000"
     def to_sqlserver_string
       datetime, usec = to_s[0..22].split('.')
       "#{datetime}.#{sprintf("%03d",usec)}"
     end
+  end
+  
+      
+  module Type
+    
+    # Make sure we get DBI::Type::Timestamp returning a string NOT a time object
+    # that represents what is in the DB before type casting and let the adapter 
+    # do the reset. DBI::DBD::ODBC will typically return a string like:
+    #   "1985-04-15 00:00:00 0"           # => "1985-04-15 00:00:00.000"
+    #   "2008-11-08 10:24:36 547000000"   # => "2008-11-08 10:24:36.547"
+    #   "2008-11-08 10:24:36 123000000"   # => "2008-11-08 10:24:36.000"
+    class SqlserverTimestamp
+      def self.parse(obj)
+        return nil if ::DBI::Type::Null.parse(obj).nil?
+        date, time, fraction = obj.split(' ')
+        "#{date} #{time}.#{sprintf("%03d",fraction)}"
+      end
+    end
+    
+    # The adapter and rails will parse our floats, decimals, and money field correctly 
+    # from a string. Do not let the DBI::Type classes create Float/BigDecimal objects 
+    # for us. Trust rails .type_cast to do what it is built to do.
+    class SqlserverForcedString
+      def self.parse(obj)
+        return nil if ::DBI::Type::Null.parse(obj).nil?
+        obj.to_s
+      end
+    end
+    
+  end
+  
+  module TypeUtil
+    
+    def self.included(klass)
+      klass.extend ClassMethods
+      class << klass
+        alias_method_chain :type_name_to_module, :sqlserver_types
+      end
+    end
+    
+    module ClassMethods
+      
+      # Capture all types classes that we need to handle directly for SQL Server 
+      # and allow normal processing for those that we do not.
+      def type_name_to_module_with_sqlserver_types(type_name)
+        case type_name
+        when /^timestamp$/i
+          DBI::Type::SqlserverTimestamp
+        when /^float|decimal|money$/i
+          DBI::Type::SqlserverForcedString
+        else
+          type_name_to_module_without_sqlserver_types(type_name)
+        end
+      end
+      
+    end
 
   end
+  
+  
+end
+
+
+if defined?(DBI::TypeUtil)
+  DBI::Type.send :include, SQLServerDBI::Type
+  DBI::TypeUtil.send :include, SQLServerDBI::TypeUtil
+elsif defined?(DBI::Timestamp) # DEPRECATED in DBI 0.4.0 and above. Remove when 0.2.2 and lower is no longer supported.
+  DBI::Timestamp.send :include, SQLServerDBI::Timestamp
 end
 
-DBI::Timestamp.send :include, SQLServerDBI::Timestamp

test/cases/column_test_sqlserver.rb

@@ -1,5 +1,6 @@
 require 'cases/sqlserver_helper'
 require 'models/binary'
+require 'models/topic'
 
 class ColumnTestSqlserver < ActiveRecord::TestCase
 
@@ -30,6 +31,30 @@ def setup
 
   end
 
+  context 'For .columns method' do
+
+    should 'return correct scales and precisions for NumericData' do
+      bank_balance = NumericData.columns_hash['bank_balance']
+      big_bank_balance = NumericData.columns_hash['big_bank_balance']
+      world_population = NumericData.columns_hash['world_population']
+      my_house_population = NumericData.columns_hash['my_house_population']
+      assert_equal [2,10], [bank_balance.scale, bank_balance.precision]
+      assert_equal [2,15], [big_bank_balance.scale, big_bank_balance.precision]
+      assert_equal [0,10], [world_population.scale, world_population.precision]
+      assert_equal [0,2], [my_house_population.scale, my_house_population.precision]
+    end
+    
+    should 'return correct null, limit, and default for Topic' do
+      tch = Topic.columns_hash
+      assert_equal false, tch['id'].null
+      assert_equal true,  tch['title'].null
+      assert_equal 255,   tch['author_name'].limit
+      assert_equal true,  tch['approved'].default
+      assert_equal 0,     tch['replies_count'].default
+    end
+
+  end
+  
 
 
 end

test/cases/sqlserver_helper.rb

@@ -15,9 +15,8 @@
 class TableWithRealColumn < ActiveRecord::Base; end
 class FkTestHasFk < ActiveRecord::Base ; end
 class FkTestHasPk < ActiveRecord::Base ; end
-class SqlServerChronic < ActiveRecord::Base
-  default_timezone = :utc
-end
+class NumericData < ActiveRecord::Base ; self.table_name = 'numeric_data' ; end
+class SqlServerChronic < ActiveRecord::Base ; default_timezone = :utc ; end
 
 # A module that we can include in classes where we want to override an active record test.