SingleLocation tables - Use a datetime throughout

Use a datetime column for the Site and PointData for consistency. This
replaces the separate time and date column for site and combines them
into one. Also adds the hybrid attribute date to the Site object to
be able to only query for dates.

Both table now carry the `datetime` column to indicate this behavior.

PR-feedback

snowexsql/api.py

@@ -118,13 +118,6 @@ def _filter_measurement_type(cls, qry, value):
     def _filter_doi(cls, qry, value):
         return qry.join(cls.MODEL.doi).filter(DOI.doi == value)
 
-    @classmethod
-    def _filter_column(cls, query_model, key):
-        if key == 'date' and query_model == PointData:
-            return PointData.date_only
-        else:
-            return getattr(query_model, key)
-
     @classmethod
     def extend_qry(cls, qry, check_size=True, **kwargs):
         if cls.MODEL is None:
@@ -164,12 +157,12 @@ def extend_qry(cls, qry, check_size=True, **kwargs):
                     if "_greater_equal" in k:
                         key = k.split("_greater_equal")[0]
                         qry = qry.filter(
-                            cls._filter_column(qry_model, key) >= v
+                            getattr(qry_model, key) >= v
                         )
                     elif "_less_equal" in k:
                         key = k.split("_less_equal")[0]
                         qry = qry.filter(
-                            cls._filter_column(qry_model, key) <= v
+                            getattr(qry_model, key) <= v
                         )
                     # Filter linked columns
                     elif k == "instrument":
@@ -189,7 +182,7 @@ def extend_qry(cls, qry, check_size=True, **kwargs):
                     # Filter to exact value
                     else:
                         qry = qry.filter(
-                            cls._filter_column(qry_model, k) == v
+                            getattr(qry_model, k) == v
                         )
                     LOG.debug(
                         f"Filtering {k} to list {v}"

snowexsql/tables/point_data.py

@@ -1,4 +1,4 @@
-from sqlalchemy import Column, Date, DateTime, Float, Integer, String
+from sqlalchemy import Column, Date, Float, Integer, String
 from sqlalchemy.ext.hybrid import hybrid_property
 
 from .base import Base
@@ -14,9 +14,6 @@ class PointData(Base, SingleLocationData, HasPointObservation):
     """
     __tablename__ = 'points'
 
-    # Date of the measurement with time
-    date = Column(DateTime)
-
     version_number = Column(Integer)
     equipment = Column(String())
     value = Column(Float)
@@ -25,15 +22,15 @@ class PointData(Base, SingleLocationData, HasPointObservation):
     units = Column(String())
 
     @hybrid_property
-    def date_only(self):
+    def date(self):
         """
         Helper attribute to only query for dates of measurements
         """
-        return self.date.date()
+        return self.datetime.date()
 
-    @date_only.expression
-    def date_only(cls):
+    @date.expression
+    def date(cls):
         """
         Helper attribute to only query for dates of measurements
         """
-        return cls.date.cast(Date)
+        return cls.datetime.cast(Date)

snowexsql/tables/single_location.py

@@ -1,11 +1,12 @@
 from geoalchemy2 import Geometry
-from sqlalchemy import Column, Float, Time
+from sqlalchemy import Column, DateTime, Float
 
 
 class SingleLocationData:
     """
     Base class for point and layer data
     """
-    time = Column(Time(timezone=True))
+    # Date of the measurement with time
+    datetime = Column(DateTime(timezone=True))
     elevation = Column(Float)
     geom = Column(Geometry("POINT"))

snowexsql/tables/site.py

@@ -1,7 +1,9 @@
-from sqlalchemy import Column, String, Date, Float, Integer, ForeignKey
-from sqlalchemy.orm import Mapped, relationship, mapped_column
 from typing import List
 
+from sqlalchemy import Column, Date, Float, ForeignKey, Integer, String
+from sqlalchemy.ext.hybrid import hybrid_property
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
 from .base import Base
 from .campaign import InCampaign
 from .doi import HasDOI
@@ -28,8 +30,6 @@ class Site(SingleLocationData, Base, InCampaign, HasDOI):
 
     name = Column(String())  # This can be pit_id
     description = Column(String())
-    # Date of the measurement
-    date = Column(Date)
 
     # Link the observer
     # id is a mapped column for many-to-many with observers
@@ -53,3 +53,17 @@ class Site(SingleLocationData, Base, InCampaign, HasDOI):
     vegetation_height = Column(String())
     tree_canopy = Column(String())
     site_notes = Column(String())
+
+    @hybrid_property
+    def date(self):
+        """
+        Helper attribute to only query for dates of measurements
+        """
+        return self.datetime.date()
+
+    @date.expression
+    def date(cls):
+        """
+        Helper attribute to only query for dates of measurements
+        """
+        return cls.datetime.cast(Date)

tests/api/test_point_measurements.py

@@ -91,7 +91,7 @@ def setup_method(self, point_data):
 
     def test_date_and_instrument(self):
         result = self.subject.from_filter(
-            date=self.db_data.date.date(),
+            date=self.db_data.datetime.date(),
             instrument=self.db_data.observation.instrument.name,
         )
         assert len(result) == 1
@@ -110,7 +110,7 @@ def test_instrument_and_limit(self, point_data_factory):
 
     def test_no_instrument_on_date(self):
         result = self.subject.from_filter(
-            date=self.db_data.date.date() + timedelta(days=1),
+            date=self.db_data.datetime.date() + timedelta(days=1),
             instrument=self.db_data.observation.instrument.name,
         )
         assert len(result) == 0
@@ -123,7 +123,7 @@ def test_unknown_instrument(self):
 
     def test_date_and_measurement_type(self):
         result = self.subject.from_filter(
-            date=self.db_data.date.date(),
+            date=self.db_data.datetime.date(),
             type=self.db_data.observation.measurement_type.name,
         )
         assert len(result) == 1
@@ -145,21 +145,21 @@ def test_observer_in_campaign(self):
         assert result.loc[0].value == self.db_data.value
 
     def test_date_less_equal(self, point_data_factory):
-        greater_date = self.db_data.date.date() + timedelta(days=1)
-        point_data_factory.create(date=greater_date)
+        greater_date = self.db_data.datetime.date() + timedelta(days=1)
+        point_data_factory.create(datetime=greater_date)
 
         result = self.subject.from_filter(
-            date_less_equal=self.db_data.date.date(),
+            date_less_equal=self.db_data.datetime.date(),
         )
         assert len(result) == 1
         assert result.loc[0].value == self.db_data.value
 
     def test_date_greater_equal(self, point_data_factory):
-        greater_date = self.db_data.date.date() - timedelta(days=1)
-        point_data_factory.create(date=greater_date)
+        greater_date = self.db_data.datetime.date() - timedelta(days=1)
+        point_data_factory.create(datetime=greater_date)
 
         result = self.subject.from_filter(
-            date_greater_equal=self.db_data.date.date(),
+            date_greater_equal=self.db_data.datetime.date(),
         )
         assert len(result) == 1
         assert result.loc[0].value == self.db_data.value

tests/db_connection.py

@@ -1,4 +1,4 @@
-from datetime import date, time
+from datetime import datetime
 
 import pytest
 from geoalchemy2.elements import WKTElement
@@ -77,9 +77,8 @@ def _add_entry(
                     session, Site, dict(name=site_name),
                     object_kwargs=dict(
                         name=site_name, campaign=campaign,
-                        date=kwargs.pop("date"),
+                        datetime=kwargs.pop("datetime"),
                         geom=kwargs.pop("geom"),
-                        time=kwargs.pop("time"),
                         elevation=kwargs.pop("elevation"),
                         observers=observer_list,
                     )
@@ -119,8 +118,7 @@ def _add_entry(
     def populated_layer(self, db):
         # Fake data to implement
         row = {
-            'date': date(2020, 1, 28),
-            'time': time(18, 48),
+            'datetime': datetime(2020, 1, 28, 18, 48),
             'elevation': 3148.2,
             'geom': WKTElement(
                 "POINT(747987.6190615438 4324061.7062127385)", srid=26912

tests/factories/point_data.py

@@ -1,4 +1,4 @@
-import datetime
+from datetime import datetime, timezone
 
 import factory
 from geoalchemy2 import WKTElement
@@ -13,7 +13,7 @@ class Meta:
         model = PointData
 
     value = 10
-    date = factory.LazyFunction(datetime.datetime.now)
+    datetime = factory.LazyFunction(lambda: datetime.now(timezone.utc))
 
     geom = WKTElement(
         "POINT(747987.6190615438 4324061.7062127385)", srid=26912

tests/factories/site.py

@@ -1,4 +1,4 @@
-import datetime
+from datetime import datetime, timezone
 
 import factory
 from geoalchemy2 import WKTElement
@@ -15,7 +15,7 @@ class Meta:
 
     name = 'Site Name'
     description = 'Site Description'
-    date = factory.LazyFunction(datetime.date.today)
+    datetime = factory.LazyFunction(lambda: datetime.now(timezone.utc))
 
     slope_angle = 0.0
     aspect = 0.0

tests/tables/test_point_data.py

@@ -6,6 +6,11 @@
 from snowexsql.tables import PointData
 
 
+@pytest.fixture
+def point_data_attributes(site_factory):
+    return site_factory.build()
+
+
 @pytest.fixture
 def point_entry_record(point_data_factory, db_session):
     point_data_factory.create()
@@ -14,23 +19,32 @@ def point_entry_record(point_data_factory, db_session):
 
 class TestPointData:
     @pytest.fixture(autouse=True)
-    def setup_method(self, point_entry_record):
+    def setup_method(self, point_entry_record, point_data_attributes):
         self.subject = point_entry_record
+        self.attributes = point_data_attributes
 
     def test_record_id(self):
         assert self.subject.id is not None
 
     def test_value_attribute(self):
         assert type(self.subject.value) is float
 
-    def test_date_attribute(self):
-        assert type(self.subject.date) is datetime
+    def test_datetime_attribute(self):
+        assert type(self.subject.datetime) is datetime
+        # The microseconds won't be the same between the site_attribute
+        # and site_record fixture. Hence only testing the difference being
+        # small. Important to subtract the later from the earlier time as
+        # the timedelta object is incorrect otherwise
+        assert (
+           self.attributes.datetime - self.subject.datetime
+       ).seconds == pytest.approx(0, rel=0.1)
 
-    def test_date_only_attribute(self):
-        assert type(self.subject.date_only) is date
+    def test_date_attribute(self):
+        assert type(self.subject.date) is date
+        assert self.subject.date == self.attributes.date
 
-    def test_elevation_attribute(self, point_data_factory):
-        assert self.subject.elevation == point_data_factory.elevation
+    def test_elevation_attribute(self):
+        assert self.subject.elevation == self.attributes.elevation
 
     def test_geom_attribute(self):
         assert isinstance(self.subject.geom, WKBElement)

tests/tables/test_site.py

@@ -26,6 +26,16 @@ def setup_method(self, site_record, site_attributes):
     def test_site_name(self, site_factory):
         assert self.subject.name == site_factory.name
 
+    def test_datetime_attribute(self):
+        assert type(self.subject.datetime) is datetime.datetime
+        # The microseconds won't be the same between the site_attribute
+        # and site_record fixture. Hence only testing the difference being
+        # small. Important to subtract the later from the earlier time as
+        # the timedelta object is incorrect otherwise
+        assert (
+            self.attributes.datetime - self.subject.datetime
+        ).seconds == pytest.approx(0, rel=0.1)
+
     def test_date_attribute(self):
         assert type(self.subject.date) is datetime.date
         assert self.subject.date == self.attributes.date