autodetect SQLiteGPKG geometry columns, normalize fields into JSON Schema types (#1088) (#1103)

pygeoapi/provider/sqlite.py

@@ -5,7 +5,7 @@
 #          Francesco Bartoli <xbartolone@gmail.com>
 #
 # Copyright (c) 2018 Jorge Samuel Mendes de Jesus
-# Copyright (c) 2022 Tom Kralidis
+# Copyright (c) 2023 Tom Kralidis
 # Copyright (c) 2020 Francesco Bartoli
 #
 # Permission is hereby granted, free of charge, to any person
@@ -91,7 +91,15 @@ class SQLiteGPKGProvider(BaseProvider):
             results = self.cursor.execute(
                 f'PRAGMA table_info({self.table})').fetchall()
             for item in results:
-                self.fields[item['name']] = {'type': item['type']}
+                json_type = None
+
+                if item['type'] in ['INTEGER', 'REAL']:
+                    json_type = 'number'
+                elif item['type'].startswith('TEXT') or item['type'] == 'BLOB':
+                    json_type = 'string'
+
+                if json_type is not None:
+                    self.fields[item['name']] = {'type': json_type}
 
         return self.fields
 
@@ -212,6 +220,9 @@ class SQLiteGPKGProvider(BaseProvider):
             self.application_id = 0
 
         if self.application_id:
+            geometry_columns_table = 'gpkg_geometry_columns'
+            geometry_columns_table_name = 'table_name'
+            geometry_columns_column_name = 'column_name'
             cursor.execute("SELECT AutoGPKGStart()")
             result = cursor.fetchall()
             if result[0][0] >= 1:
@@ -219,27 +230,37 @@ class SQLiteGPKGProvider(BaseProvider):
             else:
                 LOGGER.info("SELECT AutoGPKGStart() returned 0." +
                             "Detected GPKG but couldn't load support")
-                raise InvalidPluginError
-
-        if self.application_id:
-            self.geom_col = "geom"
+                raise InvalidPluginError()
         else:
-            self.geom_col = "geometry"
+            geometry_columns_table = 'geometry_columns'
+            geometry_columns_column_name = 'f_geometry_column'
+            geometry_columns_table_name = 'f_table_name'
 
         try:
             cursor.execute(f'PRAGMA table_info({self.table})')
             result = cursor.fetchall()
         except sqlite3.OperationalError:
-            LOGGER.error(f'Couldnt find table: {self.table}')
+            LOGGER.error(f'Could not find table: {self.table}')
             raise ProviderConnectionError()
 
+        LOGGER.debug('Determining name of geometry column')
+        cursor.execute(f"SELECT {geometry_columns_column_name} FROM {geometry_columns_table} WHERE {geometry_columns_table_name} = '{self.table}'")  # noqa
+        geometry_column = cursor.fetchall()
+
+        if geometry_column:
+            LOGGER.debug("Found geometry column")
+            self.geom_col = geometry_column[0][0]
+        else:
+            msg = 'No geometry column found'
+            LOGGER.error(msg)
+            raise ProviderConnectionError(msg)
+
         try:
             assert len(result), 'Table not found'
             assert len([item for item in result
                         if self.id_field in item]), 'id_field not present'
-
         except AssertionError:
-            raise InvalidPluginError
+            raise InvalidPluginError()
 
         self.columns = [item[1] for item in result if item[1]
                         not in [self.geom_col, self.geom_col.upper()]]

tests/test_sqlite_geopackage_provider.py

@@ -4,7 +4,7 @@
 #          Tom Kralidis <tomkralidis@gmail.com>
 #
 # Copyright (c) 2019 Just van den Broecke
-# Copyright (c) 2022 Tom Kralidis
+# Copyright (c) 2023 Tom Kralidis
 #
 # Permission is hereby granted, free of charge, to any person
 # obtaining a copy of this software and associated documentation
@@ -63,6 +63,18 @@ def config_geopackage():
     }
 
 
+def test_get_fields_sqlite(config_sqlite):
+    """Testing field definitions for sqlite3"""
+
+    fields_expected = {
+        'ogc_fid': {'type': 'number'},
+        'scalerank': {'type': 'number'}
+    }
+
+    p = SQLiteGPKGProvider(config_sqlite)
+    assert p.get_fields() == fields_expected
+
+
 def test_query_sqlite(config_sqlite):
     """Testing query for a valid JSON object with geometry for sqlite3"""
 
@@ -78,6 +90,21 @@ def test_query_sqlite(config_sqlite):
     assert geometry is not None
 
 
+def test_get_fields_geopackage(config_geopackage):
+    """Testing field definitions for geopackage"""
+
+    fields_expected = {
+        'fclass': {'type': 'string'},
+        'fid': {'type': 'number'},
+        'gid': {'type': 'number'},
+        'name': {'type': 'string'},
+        'osm_id': {'type': 'number'}
+    }
+
+    p = SQLiteGPKGProvider(config_geopackage)
+    assert p.get_fields() == fields_expected
+
+
 def test_query_geopackage(config_geopackage):
     """Testing query for a valid JSON object with geometry for geopackage"""