Buildings and levels for the floor map, and make every identifier searchable

shopdb/core/models/location.py

@@ -70,6 +70,13 @@ class Location(BaseModel):
     # chain priority 3.
     mapx = db.Column(db.Integer, comment='Default X coordinate for assets at this location')
     mapy = db.Column(db.Integer, comment='Default Y coordinate for assets at this location')
+    # Which drawing those coordinates are pixels of (ADR-017). A location is on a
+    # level as much as an asset is, and an asset with no position of its own
+    # inherits BOTH the coordinates and the level from here - inheriting the
+    # coordinates alone would draw them on whatever level the asset claims.
+    levelid = db.Column(
+        db.Integer, db.ForeignKey('maplevels.levelid'), nullable=True, index=True,
+        comment='Which level mapx/mapy are pixels of (ADR-017)')
 
     # Relationships
     locationtype = db.relationship('LocationType')