python - 从 GAE 数据存储区删除数据时出现错误 : AttributeError: 'list' object has no attribute 'fetch'

Question

queries = [query for query in QueryHistory.query().order(-QueryHistory.date)]
if(len(queries) > constants.QUERY_LIMIT_SIZE):
    que = queries[constants.QUERY_LIMIT_SIZE:]
    list_of_keys = que.fetch(keys_only = True)
    ndb.delete_multi(list_of_keys)

从数据存储中删除数据时，我收到 AttributeError: 'list' object has no attribute 'fetch' 错误。如果有人有解决方案请评论。

Answer 1

您的que是一个查询列表，您需要对列表的每个成员调用.fetch()，而不是列表本身。试试这个:

queries = [query for query in QueryHistory.query().order(-QueryHistory.date)]
if(len(queries) > constants.QUERY_LIMIT_SIZE):
    que = queries[constants.QUERY_LIMIT_SIZE:]
    for query in que:
        list_of_keys = query.fetch(keys_only = True)
        ndb.delete_multi(list_of_keys)