diff -r 9321e100a7fb -r 274efd5c769d app/soc/logic/models/grading_record.py
--- a/app/soc/logic/models/grading_record.py	Mon Jul 13 00:53:42 2009 +0200
+++ b/app/soc/logic/models/grading_record.py	Mon Jul 13 00:59:11 2009 +0200
@@ -22,7 +22,11 @@
   ]
 
 
+from google.appengine.ext import db
+
 from soc.logic.models import base
+from soc.logic.models.survey_record import grading_logic
+from soc.logic.models.survey_record import project_logic
 
 import soc.models.grading_record
 
@@ -39,5 +43,100 @@
     super(Logic, self).__init__(model=model, base_model=base_model,
                                 scope_logic=scope_logic, id_based=True)
 
+  def updateOrCreateRecordsFor(self, survey_group, project_entities):
+    """Updates or creates a GradingRecord in a batch.
+
+    Args:
+      survey_group: GradingSurveyGroup entity
+      project_entities: list of project_entities which to process
+    """
+
+    records_to_store = []
+
+    query_fields = {'grading_survey_group': survey_group}
+
+    for project_entity in project_entities:
+      # set a new project to query for
+      query_fields['project'] = project_entity
+
+      # try to retrieve an existing record
+      record_entity = self.getForFields(query_fields, unique=True)
+
+      # retrieve the fields that should be set
+      record_fields = self.getFieldsForGradingRecord(project_entity,
+                                                     survey_group,
+                                                     record_entity)
+
+      if record_entity:
+        # update existing GradingRecord
+        for key,value in record_fields.iteritems():
+          setattr(record_entity, key, value)
+      else:
+        # create a new GradingRecord
+        record_entity = self.getModel()(**record_fields)
+
+      # prepare the new/updated record for storage
+      records_to_store.append(record_entity)
+
+    # batch put and return the entities
+    return db.put(records_to_store)
+
+
+  def getFieldsForGradingRecord(self, project, survey_group,
+                                record_entity=None):
+    """Returns the fields for a GradingRecord.
+
+    See GradingRecord model for description of the grade_decision value.
+
+    Args:
+      project: Project entity
+      survey_group: a GradingSurveyGroup entity
+      record_entity an optional GradingRecord entity
+
+    Returns:
+      Dict containing the fields that should be set on a GradingRecord for this
+      GradingSurveyGroup and StudentProject
+    """
+
+    # retrieve the two Surveys, student_survey might be None
+    grading_survey = survey_group.grading_survey
+    student_survey = survey_group.student_survey
+
+    # retrieve a GradingSurveyRecord
+    survey_record_fields = {'project': project,
+                            'survey': grading_survey}
+
+    grading_survey_record = grading_logic.getForFields(survey_record_fields,
+                                                       unique=True)
+
+    if student_survey:
+      # retrieve ProjectSurveyRecord
+      survey_record_fields['survey'] = student_survey
+      project_survey_record = project_logic.getForFields(survey_record_fields, unique=True)
+    else:
+      project_survey_record = None
+
+    # set the necessary fields
+    fields = {'grading_survey_group': survey_group,
+              'project': project,
+              'mentor_record': grading_survey_record,
+              'student_record': project_survey_record}
+
+    if not record_entity or not record_entity.locked:
+      # find grading decision for new or unlocked records
+
+      if not grading_survey_record:
+        # no record found, return undecided
+        grade_decision = 'undecided'
+      elif not student_survey or project_survey_record:
+        # if the grade is True then pass else fail
+        grade_decision = 'pass' if grading_survey_record.grade else 'fail'
+      else:
+        # no ProjectSurveyRecord on file while there is a survey to be taken
+        grade_decision = 'fail'
+        fields['grade_decision'] = grade_decision
+
+    # return the fields that should be set for a GradingRecord
+    return fields
 
 logic = Logic()