Added amount value for locations api (#668)

migrations/0099.sql

@@ -10,3 +10,18 @@ ADD shopping_location_id INTEGER;
 
 ALTER TABLE stock
 ADD shopping_location_id INTEGER;
+
+DROP VIEW stock_current_locations;
+CREATE VIEW stock_current_locations
+AS
+SELECT
+	1 AS id, -- Dummy, LessQL needs an id column
+	s.product_id,
+        SUM(s.amount) as amount,
+	s.location_id AS location_id,
+	l.name AS location_name,
+	l.is_freezer AS location_is_freezer
+FROM stock s
+JOIN locations l
+	ON s.location_id = l.id
+GROUP BY s.product_id, s.location_id, l.name;