added attribute.eq(nil)

  - produces attribute IS NULL

4 files changed, 11 insertions, 2 deletions

diff --git a/lib/active_relation/extensions/array.rb b/lib/active_relation/extensions/array.rb
index 2af5832707..793c06aad8 100644
--- a/lib/active_relation/extensions/array.rb
+++ b/lib/active_relation/extensions/array.rb
@@ -7,7 +7,7 @@ class Array
     "(" + collect { |e| e.to_sql(formatter) }.join(', ') + ")"
   end
   
-  def predicate_sql
+  def inclusion_predicate_sql
     "IN"
   end
 end
\ No newline at end of file
diff --git a/lib/active_relation/extensions/nil_class.rb b/lib/active_relation/extensions/nil_class.rb
new file mode 100644
index 0000000000..729c4cada7
--- /dev/null
+++ b/lib/active_relation/extensions/nil_class.rb
@@ -0,0 +1,5 @@
+class NilClass
+  def equality_predicate_sql
+    'IS'
+  end
+end
\ No newline at end of file
diff --git a/lib/active_relation/extensions/object.rb b/lib/active_relation/extensions/object.rb
index cd51543c91..25cef989a4 100644
--- a/lib/active_relation/extensions/object.rb
+++ b/lib/active_relation/extensions/object.rb
@@ -7,6 +7,10 @@ class Object
     formatter.scalar self
   end
   
+  def equality_predicate_sql
+    '='
+  end
+  
   def metaclass
     class << self
       self
diff --git a/lib/active_relation/extensions/range.rb b/lib/active_relation/extensions/range.rb
index 0218a0ab44..d7329efe34 100644
--- a/lib/active_relation/extensions/range.rb
+++ b/lib/active_relation/extensions/range.rb
@@ -3,7 +3,7 @@ class Range
     formatter.range self.begin, self.end
   end
   
-  def predicate_sql
+  def inclusion_predicate_sql
     "BETWEEN"
   end
 end
\ No newline at end of file