我将尝试通过缩短日期时间到小时的方式来聚合记录。在mongoengine上有没有一种方法可以做到这一点并保存字段类型?
我的数据如下:
我的数据如下:
{'spent': 7, 'time_started': datetime.datetime(2015, 4, 21, 16, 2, 16, 661000)}
{'spent': 3, 'time_started': datetime.datetime(2015, 4, 21, 17, 8, 5, 415000)}
{'spent': 3, 'time_started': datetime.datetime(2015, 4, 21, 15, 52, 45, 917000)}
{'spent': 1, 'time_started': datetime.datetime(2015, 4, 21, 16, 42, 32, 313000)}
{'spent': 8, 'time_started': datetime.datetime(2015, 4, 21, 16, 35, 46, 863000)}
{'spent': 5, 'time_started': datetime.datetime(2015, 4, 21, 15, 55, 1, 217000)}
{'spent': 10, 'time_started': datetime.datetime(2015, 4, 20, 17, 41, 50, 5000)}
这是我目前的翻译:
pipeline =[
'match': {
"time_started": {
"$gte": datetime.datetime(2015, 4, 21, 0, 0, 0),
}
},
'project': {
"spent": "$spent",
"time_started": {"$dateToString": {
"format": "%Y-%m-%dT%H:00:00",
"date": "$time_started"
}}
},
'group': {
"_id": {
"time_started": "$time_started",
},
"spent_total": {"$sum": "$spent"}
}
]
它的功能很好,但是结果中的"time_started"是一个字符串,而我需要datetime(日期时间),就像这样:
{'spent_total': 16, 'time_started': datetime.datetime(2015, 4, 21, 16, 0, 0)}
{'spent_total': 3, 'time_started': datetime.datetime(2015, 4, 21, 17, 0, 0)}
{'spent_total': 8, 'time_started': datetime.datetime(2015, 4, 21, 15, 0, 0)}