bigdecimal should be typecast to a float on sqlite3. fixes #2162

activerecord/lib/active_record/connection_adapters/sqlite_adapter.rb

@@ -157,6 +157,11 @@ module ActiveRecord
         end
       end
 
+      def type_cast(value, column) # :nodoc:
+        return super unless BigDecimal === value
+
+        value.to_f
+      end
 
       # DATABASE STATEMENTS ======================================
 

activerecord/test/cases/adapters/sqlite3/quoting_test.rb

@@ -67,7 +67,7 @@ module ActiveRecord
 
         def test_type_cast_bigdecimal
           bd = BigDecimal.new '10.0'
-          assert_equal bd.to_s('F'), @conn.type_cast(bd, nil)
+          assert_equal bd.to_f, @conn.type_cast(bd, nil)
         end
 
         def test_type_cast_unknown

activerecord/test/cases/base_test.rb

@@ -1113,6 +1113,17 @@ class BasicsTest < ActiveRecord::TestCase
     self.table_name = 'numeric_data'
   end
 
+  def test_big_decimal_conditions
+    m = NumericData.new(
+      :bank_balance => 1586.43,
+      :big_bank_balance => BigDecimal("1000234000567.95"),
+      :world_population => 6000000000,
+      :my_house_population => 3
+    )
+    assert m.save
+    assert_equal 0, NumericData.where("bank_balance > ?", 2000.0).count
+  end
+
   def test_numeric_fields
     m = NumericData.new(
       :bank_balance => 1586.43,