Remove unused attribute.

accountant/models/operations.py

@@ -64,23 +64,6 @@ class Operation(db.Model):
         server_default=db.false()
     )
 
-    sold = db.column_property(
-        db.func.sum(
-            db.case(
-                whens={canceled: db.text("0")},
-                else_=value
-            )
-        ).over(
-            partition_by=[account_id],
-            order_by=[
-                "operation_date",
-                db.desc("value"),
-                db.desc("label"),
-                id
-            ]
-        ).label("sold")
-    )
-
     def __init__(self, label, value, account_id, operation_date=None,
                  category=None, pointed=False, confirmed=True, canceled=False,
                  scheduled_operation_id=None):