Revised error handling for duplicate datetimes.

Previous implementation of #510 meant that any database related exception would result in 500. As suggested in #538, duplicate data being sent to the server does not necessarily constitute an error from the external perspective. This commit introduce code that pass on exceptions for primary key violations (duplicate resultid and datetime) and will still return a 201.

src/dataloaderservices/views.py

@@ -41,6 +41,7 @@
 #PRT - temporary work around after replacing InfluxDB but not replacement models
 import sqlalchemy
 from sqlalchemy.sql import text
+import psycopg2
 from django.conf import settings
 _dbsettings = settings.DATABASES['odm2']
 _connection_str = f"postgresql://{_dbsettings['USER']}:{_dbsettings['PASSWORD']}@{_dbsettings['HOST']}:{_dbsettings['PORT']}/{_dbsettings['NAME']}"
@@ -609,6 +610,14 @@ def post(self, request, format=None):
 
             try:
                 query_result = InsertTimeseriesResultValues(result_value)
+            except sqlalchemy.exc.IntegrityError as e:
+                if hasattr(e, 'orig'): 
+                    if isinstance(e.orig, psycopg2.errors.UniqueViolation):
+                        pass #data is already in database
+                    else:
+                        errors.append(f"Failed to INSERT data for uuid('{result.result_uuid}')")
+                else:
+                    errors.append(f"Failed to INSERT data for uuid('{result.result_uuid}')")
             except Exception as e:
                 errors.append(f"Failed to INSERT data for uuid('{result.result_uuid}')")