diff --git a/src/caosadvancedtools/models/data_model.py b/src/caosadvancedtools/models/data_model.py
index 266414893bcdf1ab45ee1345fc549e15f4a66250..1390cf2e45b83c7fd715e674706bc98173db4ebf 100644
--- a/src/caosadvancedtools/models/data_model.py
+++ b/src/caosadvancedtools/models/data_model.py
@@ -111,8 +111,11 @@ class DataModel(dict):
         existing_entities = db.Container().extend(
             DataModel.entities_without(
                 self.values(), [e.name.lower() for e in non_existing_entities]))
+
         self.sync_ids_by_name(tmp_exist)
 
+
+
         if len(non_existing_entities) > 0:
             if verbose:
                 print("New entities:")
@@ -174,7 +177,7 @@ class DataModel(dict):
         Args
         ----
         entities : iterable
-            The entities to be retrieved.  This object will not be moidified.
+            The entities to be retrieved. This object will not be modified.
 
         Raises
         ------
diff --git a/src/caosadvancedtools/models/parser.py b/src/caosadvancedtools/models/parser.py
index 964cf1f5679b4b9bcdb0654393b21d8cee9b45ad..4fa529aae410b2d5fafd1bd57dfd7c6194fe8124 100644
--- a/src/caosadvancedtools/models/parser.py
+++ b/src/caosadvancedtools/models/parser.py
@@ -341,37 +341,38 @@ debug : bool, optional
                                               f"invalid keyword in line {entity['__line__']}:", 1)
                 raise ValueError(err_str, *err.args[1:]) from err
 
+        # TODO: functionality commented out, to be able to test failing test first.
         # Update properties that are part of record types:
         # e.g. add their datatypes, units etc..
         # Otherwise comparison of existing models and the parsed model become difficult.
-        for name, ent in self.model.items():
-            if not isinstance(ent, db.RecordType):
-                continue
-            props = ent.get_properties()
-            for prop in props:
-                if prop.name in self.model:
-                    model_prop = self.model[prop.name]
-                    # The information must be missing, we don't want to overwrite it accidentally:
-                    if prop.datatype is not None and prop.datatype != model_prop.datatype:
-                        # breakpoint()
-                        raise RuntimeError("datatype must not be set, here. This is probably a bug.")
-                    if prop.unit is not None and prop.unit != model_prop.unit:
-                        # continue
-                        raise RuntimeError("unit must not be set, here. This is probably a bug.")
-                    if prop.description is not None and prop.description != model_prop.description:
-                        # continue
-                        raise RuntimeError("description must not be set, here. This is probably a bug.")
-
-                    # If this property has a more detailed definition in the model,
-                    # copy over the information:
-
-                    if isinstance(model_prop, db.RecordType):
-                        # in this case the datatype equals the name of the record type:
-                        prop.datatype = prop.name
-                    else:
-                        prop.datatype = model_prop.datatype
-                        prop.unit = model_prop.unit
-                        prop.description = model_prop.description
+        # for name, ent in self.model.items():
+        #     if not isinstance(ent, db.RecordType):
+        #         continue
+        #     props = ent.get_properties()
+        #     for prop in props:
+        #         if prop.name in self.model:
+        #             model_prop = self.model[prop.name]
+        #             # The information must be missing, we don't want to overwrite it accidentally:
+        #             if prop.datatype is not None and prop.datatype != model_prop.datatype:
+        #                 # breakpoint()
+        #                 raise RuntimeError("datatype must not be set, here. This is probably a bug.")
+        #             if prop.unit is not None and prop.unit != model_prop.unit:
+        #                 # continue
+        #                 raise RuntimeError("unit must not be set, here. This is probably a bug.")
+        #             if prop.description is not None and prop.description != model_prop.description:
+        #                 # continue
+        #                 raise RuntimeError("description must not be set, here. This is probably a bug.")
+        #
+        #             # If this property has a more detailed definition in the model,
+        #             # copy over the information:
+        #
+        #             if isinstance(model_prop, db.RecordType):
+        #                 # in this case the datatype equals the name of the record type:
+        #                 prop.datatype = prop.name
+        #             else:
+        #                 prop.datatype = model_prop.datatype
+        #                 prop.unit = model_prop.unit
+        #                 prop.description = model_prop.description
 
         return DataModel(self.model.values())
 
diff --git a/unittests/test_yaml_model_parser.py b/unittests/test_yaml_model_parser.py
index 574b41da25e40984c0a1eef62f39080c88f1d1e0..56c8672b0e073101a38329037d7006e99b88a359 100644
--- a/unittests/test_yaml_model_parser.py
+++ b/unittests/test_yaml_model_parser.py
@@ -27,6 +27,8 @@ from caosadvancedtools.models.parser import (TwiceDefinedException,
                                              parse_model_from_string,
                                              parse_model_from_yaml)
 
+from unittests.mock import Mock
+
 from linkahead.apiutils import compare_entities
 
 
@@ -645,7 +647,7 @@ RT2:
 }"""
 
 
-def test_comparison_yaml_model():
+def test_comparison_yaml_model(capfd):
     """
     Test for this issue:
     https://gitlab.indiscale.com/caosdb/src/caosdb-advanced-user-tools/-/issues/130
@@ -707,7 +709,24 @@ test_reference:
     c2 = compare_entities(model["RT1"], entities[1])
     c3 = compare_entities(model["RT2"], entities[2])
     c4 = compare_entities(model["test_reference"], entities[3])
+    for cs in (c1, c2, c3, c4):
+        assert "id" not in cs[0]
+        assert "id" in cs[1]
+
+    mq = Mock()
+    def mq_init(self, query):
+        self.query = query
+
+    def mq_execute(self, unique=True):
+        pass
+
+    mq.__init__ = mq_init
+    mq.execute.side_effect = mq_execute
 
+    caosadvancedtools.models.parser.db.Query = mq
 
+    model.sync_data_model(True, True)
 
+    stdout, stderr = capfd.readouterr()
 
+  # TODO: test that there were no changes required