added update db script

update_db.py

@@ -0,0 +1,12 @@
+from lapp import create_app
+import sqlalchemy as sa
+from models import db, Item
+
+app = create_app()
+app.app_context().push()
+query = sa.select(Item)  #.where(Item.quantity == 0)
+items = db.session.scalars(query).all()
+
+# items=Item.query.filter_by(quantity='').all()
+for i in items:
+    print(f"{i.label} {i.quantity} {i.unit}")