[_600] prevent case-sensitive testing with BETWEEN where infeasible

Author: d-w-moore

irods/test/query_test.py

@@ -44,16 +44,49 @@ def rows_returned(query):
 
 
 class TestQuery(unittest.TestCase):
+
+    _csq = None
+
     Iterate_to_exhaust_statement_table = range(IRODS_STATEMENT_TABLE_SIZE + 1)
 
     More_than_one_batch = 2 * MAX_SQL_ROWS  # may need to increase if PRC default page
     #   size is increased beyond 500
 
     register_resc = ""
 
+    @property
+    def case_sensitive_testing_feasible(self):
+        """
+        Return result of the probe into whether lexical order of query columns has been found compatible with
+        case sensitive operators such as >, <, between.  (MySQL can fail in the default DB configuration,
+        whereas PostgreSQL does not).
+        """
+        return self._csq in (True,)
+
+    @staticmethod
+    def _query_columns_case_sensitive_by_default(ses):
+        home = helpers.home_collection(ses)
+        data_objs = []
+        try:
+            for x in ('a', 'b', 'A', 'B'):
+                data_objs.append(ses.data_objects.create(f'{home}/{x}'))
+            lower = { r[DataObject.name] for r in ses.query(DataObject.name).filter(DataObject.name >= 'a', DataObject.name <= 'b') }
+            if {'A','B'} & lower:
+                return False
+            upper = { r[DataObject.name] for r in ses.query(DataObject.name).filter(DataObject.name >= 'A', DataObject.name <= 'B') }
+            if {'a','b'} & upper:
+                return False
+            return True
+        finally:
+            for d in data_objs:
+              d.unlink(force=True)
+
     @classmethod
     def setUpClass(cls):
         with helpers.make_session() as sess:
+            if cls._csq is None:
+                cls._csq = cls._query_columns_case_sensitive_by_default(sess)
+
             resource_name = helpers.get_register_resource(sess)
             if resource_name:
                 cls.register_resc = resource_name
@@ -214,28 +247,25 @@ def test_files_query_case_sensitive(self):
         self.assertEqual(len(result12), 0)
 
         # BETWEEN tests
-
-        # TODO(#600): Uncomment these lines and/or make a new test when database flavor can be detected.
-        # The resultset for BETWEEN queries can differ from database to database.
-
-        # result13 = self.sess.query(DataObject.name).filter(
-        #    Collection.name == self.coll_path).filter(
-        #    Between(DataObject.name, [self.case_sensitive_obj_name1,
-        #                              self.case_sensitive_obj_name1 + "_"])).all()
-        # self.assertTrue(result13.has_value(self.case_sensitive_obj_name1))
-        # self.assertEqual(len(result13), 1)
-
-        # result14 = self.sess.query(DataObject.name).filter(
-        #    Collection.name == self.coll_path).filter(
-        #    Between(DataObject.name, [str.lower(self.case_sensitive_obj_name1),
-        #                              str.lower(self.case_sensitive_obj_name1) + "_"])).all()
-        # self.assertEqual(len(result14), 0)
-
-        # result15 = self.sess.query(DataObject.name).filter(
-        #    Collection.name == self.coll_path).filter(
-        #    Between(DataObject.name, [str.upper(self.case_sensitive_obj_name1),
-        #                              str.upper(self.case_sensitive_obj_name1) + "_"])).all()
-        # self.assertEqual(len(result15), 0)
+        if self.case_sensitive_testing_feasible:
+            result13 = self.sess.query(DataObject.name).filter(
+               Collection.name == self.coll_path).filter(
+               Between(DataObject.name, [self.case_sensitive_obj_name1,
+                                         self.case_sensitive_obj_name1 + "_"])).all()
+            self.assertTrue(result13.has_value(self.case_sensitive_obj_name1))
+            self.assertEqual(len(result13), 1)
+
+            result14 = self.sess.query(DataObject.name).filter(
+               Collection.name == self.coll_path).filter(
+               Between(DataObject.name, [str.lower(self.case_sensitive_obj_name1),
+                                         str.lower(self.case_sensitive_obj_name1) + "_"])).all()
+            self.assertEqual(len(result14), 0)
+
+            result15 = self.sess.query(DataObject.name).filter(
+               Collection.name == self.coll_path).filter(
+               Between(DataObject.name, [str.upper(self.case_sensitive_obj_name1),
+                                         str.upper(self.case_sensitive_obj_name1) + "_"])).all()
+            self.assertEqual(len(result15), 0)
 
     def test_files_query_case_insensitive(self):
         # This tests that GenQueries are case-insensitive when the case_sensitive