这是我的pymongo调用方式
from pymongo import MongoClient
client = MongoClient('localhost', 27017)
db = client['somedb']
collection = db.some_details
pipe = [{'$group': {'_id': '$mvid', 'count': {'$sum': 1}}}]
TestOutput = db.collection.aggregate(pipeline=pipe)
print(list(TestOutput))
client.close()
由于某些原因,结果列表为空,而在Robomongo中我得到了非空输出。
格式是否不正确?
精确的Robomongo查询如下:
db.some_details.aggregate([{$group: {_id: '$mvid', count: {$sum: 1}}}])
更新 输出结果如下:
{
"result" : [
{
"_id" : "4f973d56a64facfaa7c3r4rf262ad5be695eef329aff7ab4610ddedfb8137427",
"count" : 84.0000000000000000
},
{
"_id" : "a134106e1a1551d296fu777cedc933e7df2d0a9bc5f41de047aba3ee29bace78",
"count" : 106.0000000000000000
},
],
"ok" : 1.0000000000000000
}
db
的结果是什么? - styvane