Merge pull request #186 from VForWaTer/location_nullable

entries.location nullable + db revision

metacatalog/__version__.py

@@ -1 +1 @@
-__version__ = '0.6.0'
+__version__ = '0.6.1'

metacatalog/api/add.py

@@ -508,7 +508,14 @@ def add_entry(session, title, author, location, variable, abstract=None, externa
         on id (int) or organisation_name (str).
     location : str, tuple
         Can be either a WKT of a EPSG:4326 location, or the coordinates as a
-        tuple. It has to be (X,Y), to (longitude, latitude)
+        tuple. It has to be (X,Y), to (longitude, latitude).
+
+        .. versionchanged:: 0.6.1
+        A POINT location should be specified here if there is a physical measurement 
+        point that is different from the centroid of the spatial extent (e.g., 
+        discharge measurement with the extent of the catchment).
+        Otherwise, ``Datasource.spatial_scale.extent`` should be used to specify the
+        location of the measured data.
     variable : int, str
         **Full** variable name (str) or ID (int) of the data described by the Entry.
     abstract : str

metacatalog/db/revisions/__init__.py

@@ -10,6 +10,7 @@
     rev8,
     rev9,
     rev10,
+    rev11,
 )
 
 revisions = {
@@ -24,4 +25,5 @@
     8: rev8,
     9: rev9,
     10: rev10,
+    11: rev11,
 }

metacatalog/db/revisions/rev11.py

@@ -0,0 +1,46 @@
+"""
+Metacatalog database revision
+-----------------------------
+date: 2022-10-05T14:41:32.055433
+
+revision #11
+
+Make column entries.location nullable (raster data do not have a POINT location).
+Attention, the downgrade sets everywhere where entries.location == NULL to 
+(POINT 0 0), which may not correspond to the state of the database before upgrading,
+so the revision upgrade cannot be undone. 
+
+"""
+from sqlalchemy.orm import Session
+from metacatalog import api, models
+
+UPGRADE_SQL = """
+-- entries.location nullable
+ALTER TABLE entries ALTER COLUMN location DROP NOT NULL;
+COMMIT;
+"""
+
+DOWNGRADE_SQL = """
+-- replace eventually existing NULL values with (POINT 0 0)
+UPDATE entries SET location = 'SRID=4326; POINT (0 0)' WHERE location IS NULL;
+COMMIT; 
+-- entries.location not nullable
+ALTER TABLE entries ALTER COLUMN location SET NOT NULL;
+COMMIT;
+"""
+
+# define the upgrade function
+def upgrade(session: Session):
+    print('run update')
+    # make entries.location nullable
+    with session.bind.connect() as con:
+        con.execute(UPGRADE_SQL)
+
+
+# define the downgrade function
+def downgrade(session: Session):
+    print('run downgrade')
+    # make entries.location not nullable
+    with session.bind.connect() as con:
+        con.execute(DOWNGRADE_SQL)
+

metacatalog/db/views/locations.sql

@@ -0,0 +1,39 @@
+--CREATE OR REPLACE VIEW locations_realdata AS
+select 
+	st_asewkt(t.point_location),
+	t.*,
+	st_area(t.geom::geography) as "area_sqm"
+from 
+(SELECT 
+entries.id,
+	case when entries.location is not null then
+		entries.location
+	else 
+		case when spatial_scales.extent is not null then
+			st_centroid(spatial_scales.extent)
+		else 
+ 			case when entries.geom is not null then
+ 				st_centroid(entries.geom)
+ 			else
+				null::geometry
+ 			end
+		end
+	end  
+	as point_location
+	,
+ 	case when entries.geom is not null then
+ 		entries.geom
+ 	else
+		case when spatial_scales.extent is not null then
+			spatial_scales.extent
+		else 
+			entries.location
+		end 
+	end
+ 	as "geom"
+FROM entries
+LEFT JOIN datasources ON entries.datasource_id = datasources.id
+LEFT JOIN spatial_scales ON spatial_scales.id = datasources.spatial_scale_id
+ ) as t
+
+order by t.id asc

metacatalog/models/datasource.py

@@ -13,6 +13,7 @@
 
 from metacatalog.db.base import Base
 from metacatalog.ext import extension
+from metacatalog.util.exceptions import MetadataMissingError
 
 
 class DataSourceType(Base):
@@ -337,9 +338,12 @@ class SpatialScale(Base):
         cell size, which only applies to gridded datasets. Use the
         :attr:`resolution_str` property for a string representation
     extent : geoalchemy2.Geometry
-        The spatial extent of the dataset is given as a ``'POLYGON'``. While
-        metacatalog is capable of storing any kind of valid POLYGON as extent,
-        it is best practice to allow only Bounding Boxes on upload.
+        The spatial extent of the dataset is given as a ``'POLYGON'``. 
+        .. versionchanged:: 0.6.1
+        From this ``POLYGON``, a bounding box and the centroid are internally
+        calculated.
+        To specify a point location here, use the same value for easting and
+        westing and the same value for northing and southing.
     support : float
         The support gives the spatial validity for a single observation.
         It specifies the spatial extent at which an observed value is valid.
@@ -607,8 +611,12 @@ def create_scale(self, resolution, extent, support, scale_dimension, commit=Fals
         # get the correct class
         if scale_dimension.lower() == 'temporal':
             Cls = TemporalScale
+            if self.temporal_scale is not None:
+                raise MetadataMissingError('Temporal scale already exists. You can edit that one.')
         elif scale_dimension.lower() == 'spatial':
             Cls = SpatialScale
+            if self.spatial_scale is not None:
+                raise MetadataMissingError('Spatial scale already exists. You can edit that one.')
         else:
             raise AttributeError("scale_dimension has to be in ['temporal', 'spatial']")
 

metacatalog/models/entry.py

@@ -68,6 +68,13 @@ class Entry(Base):
         Usually an unque ID field of other data-storage solutions. The
         exernal_id is only stored for reference reasons.
     location : str, tuple
+        .. versionchanged:: 0.6.1
+        A POINT location should be specified here if there is a physical measurement 
+        point that is different from the centroid of the spatial extent (e.g., 
+        discharge measurement with the extent of the catchment).
+        Otherwise, ``Datasource.spatial_scale.extent`` should be used to specify the
+        location of the measured data.
+
         The location as a POINT Geometry in unprojected WGS84 (EPSG: 4326).
         The location is primarily used to show all Entry objects on a map, or
         perform geo-searches. If the data-source needs to store more complex
@@ -165,7 +172,7 @@ class Entry(Base):
     title = Column(String(512), nullable=False)
     abstract = Column(String)
     external_id = Column(String)
-    location = Column(Geometry(geometry_type='POINT', srid=4326), nullable=False)
+    location = Column(Geometry(geometry_type='POINT', srid=4326), nullable=True)
     geom = Column(Geometry)
     version = Column(Integer, default=1, nullable=False)
     latest_version_id = Column(Integer, ForeignKey('entries.id'), nullable=True)