我有一个空的集合并且有数千个要处理的条目(条目可能具有我希望同时使用更新和插入的减少量)。 python代码(使用pymongo)我写道:
for mydoc in alldocs:
key = {'myid': mydoc['myid']}
data = process_doc(mydoc) # returns simple dictionary
db.mydocs.update(key, {"$set": data}, upsert = True)
以下代码无法执行任何插入操作。该系列仍然是空的。但是,当我删除$ set并使用简单的数据时,它工作正常。我不能在upsert中使用$ set吗?我想要$ set的原因是BSON的预先存在的字段不会受到影响。有人可以指导。我真的无法弄清楚该怎么做。
可重复使用的代码:
from pymongo import Connection
DB_CONTENT_BASE_KEY = 'contentbase'
def connect_to_db(dbname, hostname = 'localhost', portno = 27017, **kwargs):
connection = Connection(hostname, portno)
dbConnection = connection[dbname]
return dbConnection
class MetawebCustomCollectionBuilder(object):
# key ought to be a dictionary to filter results from contentbase.
def __init__(self, inDbConfig, outDbConfig, key = {}, verbose = False):
self.verbose = verbose
self.inDbConfig = inDbConfig
self.inDb = connect_to_db(**inDbConfig)
self.outDbConfig = outDbConfig
self.outDb = connect_to_db(**outDbConfig)
self.inDbContentBase = self.inDb[self.inDbConfig[DB_CONTENT_BASE_KEY]]
self.outDbContentBase = self.outDb[self.outDbConfig[DB_CONTENT_BASE_KEY]]
self.key = key
self.in_db_collection_constraints()
self.out_db_collection_constraints()
def in_db_collection_constraints(self):
self.inDbContentBase.ensure_index('mid')
if self.verbose: print("Assured index on mid for inDbContentBase...")
def out_db_collection_constraints(self):
self.outDbContentBase.ensure_index('mid')
if self.verbose: print("Assured index on mid for outDbContentBase...")
def process_in_record(self, inRecord):
outRecord = inRecord # [YET TO] continue from here...
return outRecord
def transit_collection(self):
for record in self.inDbContentBase.find(self.key):
outRecord = self.process_in_record(record)
key = {'mid':outRecord['mid']}
data = outRecord
print key
self.outDbContentBase.update(key, {"$set": data}, True)
if self.verbose: print 'Done with transiting collection from in DB to out DB'
def cleanup_out_collection(self):
pass
def in_db_sandbox(self):
# To have tests and analytics placed in here corresponding to inDb.
pass
if __name__ == '__main__':
inDbConfig = {'dbname':'metaweb', 'contentbase': 'content'}
outDbConfig = {'dbname': 'similarkind', 'contentbase': 'content'}
mccb = MetawebCustomCollectionBuilder(inDbConfig, outDbConfig, verbose = True)
mccb.transit_collection()
必须在db中存在一个现有的数据库。从这个集合中我想创建一个新的修改集合。
答案 0 :(得分:8)
您的声明错误
>>> import pymongo
>>> c = pymongo.Connection()
>>> db = c.mydb
>>> db.mydocs.find().count()
0
>>> db.mydocs.update({'myid': '438'}, {"$set": {'keyA':'valueA'}}, upsert = True)
>>> db.mydocs.find().count()
1
>>> db.mydocs.find_one()
{u'myid': u'438', u'keyA': u'valueA', u'_id': ObjectId('504c2fd1a694cc9624bbd6a2')}