Python Pymongo 查找和修改
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Pymongo find and modify
提问by user2950162
I have a find query in a mongodb collection and would like this query to also update a field... something like this...
我在 mongodb 集合中有一个查找查询，并且希望这个查询也更新一个字段......像这样......
db = pymongo.MongoClient(DB_HOST)[COLLECTION][Product]
new_posts = db.find({'type':{'$ne':'overview'}, 'indice':0, 'thread_id':{'$nin':front_db_ids}, 'updated':{'$exists':False}},{'_id': 0}) + {{'$set': {'updated':'yes'}}, multi=True
I found the findandmodify method but could not find any example of how to use it...
我找到了 findandmodify 方法，但找不到如何使用它的任何示例...
Thanks in advance for any help!
在此先感谢您的帮助！
采纳答案by namit
refer the documentation,
for example
参考文档，例如
db.update({"_id": acs_num}, {"$set": mydata}, upsert = True)
or find_and_modifyaccording to docssays Returns either the object before or after modification based on new parameter. If no objects match the query and upsert is false, returns None. If upserting and new is false, returns {}
或find_and_modify根据文档说Returns either the object before or after modification based on new parameter. If no objects match the query and upsert is false, returns None. If upserting and new is false, returns {}
for example:
例如：
In [1]: from pymongo import MongoClient
In [2]: client = MongoClient("mongodb://localhost:27017")
...: db = client["testdb"]
...: mycollection = db["mydb"]
...:
In [3]: import datetime
...: post1 = {"author": "Mike", "text": "My first blog post!", "tags": ["mongodb", "python", "pymongo"], "date": datetime.datetime.utcnow()}
...:
In [4]: mycollection.insert(post1)
Out[4]: ObjectId('535fd580c314f91d28c35ee1')
In [5]: [x for x in mycollection.find()]
Out[5]:
[{u'_id': ObjectId('535fd580c314f91d28c35ee1'),
u'author': u'Mike',
u'date': datetime.datetime(2014, 4, 29, 16, 38, 15, 457000),
u'tags': [u'mongodb', u'python', u'pymongo'],
u'text': u'My first blog post!'}]
In [6]: mycollection.find_and_modify(query={'author':'Mike'}, update={"$set": {'author': "Mike2"}}, upsert=False, full_response= True)
Out[6]:
{u'lastErrorObject': {u'n': 1, u'updatedExisting': True},
u'ok': 1.0,
u'value': {u'_id': ObjectId('535fd580c314f91d28c35ee1'),
u'author': u'Mike',
u'date': datetime.datetime(2014, 4, 29, 16, 38, 15, 457000),
u'tags': [u'mongodb', u'python', u'pymongo'],
u'text': u'My first blog post!'}}
In [7]: [ x for x in mycollection.find()]
Out[7]:
[{u'_id': ObjectId('535fd580c314f91d28c35ee1'),
u'author': u'Mike2',
u'date': datetime.datetime(2014, 4, 29, 16, 38, 15, 457000),
u'tags': [u'mongodb', u'python', u'pymongo'],
u'text': u'My first blog post!'}]
回答by Sid Holland
For those that came here after Googling find_and_modifyand discovered it is deprecated (in PyMongo version 3.0, I think), the replacement is find_one_and_update.
对于那些在谷歌搜索后find_and_modify发现它已被弃用的人（我认为在 PyMongo 3.0 版中），替换为find_one_and_update.
Let's say you have a collection called countersand want to increment one of the counters:
假设您有一个名为的集合counters并希望增加其中一个计数器：
db.counters.find_one_and_update({"_id": "counter-id"}, {"$inc":{"sequence_value":1}})
If you want the new document returned, instead of the original pre-updated one, the parameter to pass is newand not, as most documentation states, returnNewDocument:
如果您希望返回新文档，而不是原始的预更新文档，则传递的参数是new而不是，正如大多数文档所述returnNewDocument：
db.counters.find_one_and_update({"_id": "counter-id"}, {"$inc":{"sequence_value":1}}, new=True)
