Question

您好我想更新一些与查询匹配的文档。因此，对于每个文档，我想更新字段'parent_id'当且仅当此文档具有ID greater then，即6

时

        for result in results:
            db.update(set('parent_id', current_element_id), 
                      result.get('id') > current_element_id )

错误：

Traceback (most recent call last):
  File "debug.py", line 569, in <module>
    convertxml=parse(xmlfile, force_list=('interface',))
  File "debug.py", line 537, in parse
    parser.Parse(xml_input, True)
  File "..\Modules\pyexpat.c", line 468, in EndElement
  File "debug.py", line 411, in endElement
    db.update(set('parent_id', current_element_id), result.get('id') > current_element_id )
  File "C:\ProgramData\Miniconda3\lib\site-packages\tinydb\database.py", line 477, in update
    cond, doc_ids
  File "C:\ProgramData\Miniconda3\lib\site-packages\tinydb\database.py", line 319, in process_elements
    if cond(data[doc_id]):
TypeError: 'bool' object is not callable

应该更新的文档示例：

...,
{'URI': 'http://www.john-doe/',
 'abbr': 'IDD',
 'affiliation': 'USA',
 'closed': False,
 'created': '2018-06-01 22:49:02.927347',
 'element': 'distrbtr',
 'id': 7,
 'parent_id': None
 },...

在 tinydb 的documentation中，我看到我可以使用设置。否则，如果我不使用设置，则会更新所有我不想要的文档db.update(dict)。

Answer 1

使用文档的write_back到replace部分文档更好

>>> docs = db.search(User.name == 'John')
[{name: 'John', age: 12}, {name: 'John', age: 44}]
>>> for doc in docs:
...     doc['name'] = 'Jane'
>>> db.write_back(docs)  # Will update the documents we retrieved
>>> docs = db.search(User.name == 'John')
[]
>>> docs = db.search(User.name == 'Jane')
[{name: 'Jane', age: 12}, {name: 'Jane', age: 44}]

根据我的情况实施

for result in results:
    if result['parent_id'] != None:
        result['parent_id']  = current_element_id
db.write_back(results)

tinydb：如何使用条件更新文档

1 个答案: