diff --git a/composer/report/base.py b/composer/report/base.py
index fddcdb0..3ca43e1 100644
--- a/composer/report/base.py
+++ b/composer/report/base.py
@@ -133,6 +133,9 @@ class Report(Template):
 
     def getPresentationFormats(self):
         return [dict(renderer='default', title='Default')]
+    
+    def getCategoryFields(self):
+        return [f for f in self.fields if 'category' in f.executionSteps]
 
 
 class BaseQueryCriteria(Component):
diff --git a/composer/report/result.py b/composer/report/result.py
index f947ce4..6b010cc 100644
--- a/composer/report/result.py
+++ b/composer/report/result.py
@@ -53,21 +53,41 @@ class Row(BaseRow):
     @staticmethod
     def getContextAttr(obj, attr):
         return getattr(obj.context, attr)
+    
+    def getCategories(self):
+        return [self.getRawValue(f.__name__) for f in 
+                    self.parent.context.fields if 'category' in f.executionSteps]
 
 
 class ResultSet(object):
 
     def __init__(self, context, data, rowFactory=Row,
-                 sortCriteria=None, queryCriteria=BaseQueryCriteria()):
+                 sortCriteria=None, queryCriteria=BaseQueryCriteria(),
+                 filterDublicate=False):
         self.context = context  # the report or report instance
         self.data = data
         self.rowFactory = rowFactory
         self.sortCriteria = sortCriteria
         self.queryCriteria = queryCriteria
+        self.filterDublicate = filterDublicate
         self.totals = BaseRow(None, self)
+        
+    def filterDublicateRows(self, result):
+        res = []
+        for row in result:
+            add = True
+            for r in res:
+                for f in self.categoryColumns:
+                    if row.getRawValue(f.__name__) == r.getRawValue(f.__name__):
+                        add = False
+            if add:
+                res.append(row)
+        return res
 
     def getResult(self):
         result = [self.rowFactory(item, self) for item in self.data]
+        if self.filterDublicate:
+            result = [row for row in self.filterDublicateRows(result)]
         result = [row for row in result if self.queryCriteria.check(row)]
         if self.sortCriteria:
             result.sort(key=lambda x: [f.getSortValue(x) for f in self.sortCriteria])
@@ -82,3 +102,7 @@ class ResultSet(object):
     def displayedColumns(self):
         return self.context.getActiveOutputFields()
 
+    @Lazy
+    def categoryColumns(self):
+        return self.context.getCategoryFields()
+