python MongoDB 自动生成创建时间与更新时间（create_time/update_time）

一.实例

# 类似 MySQL 以下语句，并更新时间
INSERT INTO ... ON DUPLICATE KEY UPDATE ...
# 第一次执行时，生成 create_time 和 update_time
# 第二次执行时，更新 update_time

二.Mongo Shell

方式一.

db.student.updateOne(
    { sno: 1 },
    {
        $setOnInsert: { create_time: new Date() },
        $set: { sname: "qbit", update_time: new Date() }
    },
    {
        upsert: true
    }
)

方式二（currentDate）

/*
约等于上面的语句。
通常下面的语句在新建 document 时，
update_time 会比 create_time 晚一点。
因为 new Date() 是 js 函数，在客户端生成；
currentDate 获取的是服务器时间
*/
db.student.updateOne(
    { sno: 1 },
    {
        $currentDate: {
            update_time: true
        },
        $setOnInsert: { create_time: new Date() },
        $set: { sname: "qbit" }
    },
    {
        upsert: true
    }
)

三.pymongo

# -*- coding: utf-8 -*-
# @Time    : 2022/1/14 9:35
# @Author  : Cocktail_py

from datetime import datetime, tzinfo, timedelta
import pytz
import pymongo
from bson.codec_options import CodecOptions


class MongoHelper(object):
    def __init__(self, conn_url):
        # 设置读取来时间的时区
        options = CodecOptions(tz_aware=True, tzinfo=pytz.timezone('Asia/Shanghai'))
        self.db = pymongo.MongoClient(conn_url, maxPoolSize=None).get_database(codec_options=options)

    def insert_or_update(self, table_name: str,
                         data_dict: dict,
                         ):
        """
        插入或更新
        :param table_name: MongoDB 集合名
        :param data_dict: 带_id主键的数据
        :return:
        """

        coll = self.db[table_name]
        # 0 区
        dt0 = datetime.utcnow()
        _id = data_dict.get("id", "")
        if not _id:
            raise Exception("数据存储需要唯一id")
        data_dict['update_time'] = dt0
        update_dict = {'$set': data_dict, '$setOnInsert': {'create_time': dt0, 'delete_time': 0}}
        return coll.update_one({"_id": _id}, update_dict, upsert=True)

    def get_all(self, table_name, data_dict={}, field_dict={}, sort_field="create_time", sort_type=pymongo.DESCENDING,
                limit=0):
        """
        获取相应集合的数据
        :param table_name: MongoDB 集合名
        :param data_dict: 查询条件
        :param field_dict: 需要返回的字段 {"A":1,"B":0} 返回A字段,返回字段中排出B字段
        :param sort_field: 排序字段
        :param sort_type: 排序类型
        :param limit: 条数
        :return:
        """
        coll = self.db[table_name]
        _id = data_dict.get("id", "")
        if _id:
            data_dict["_id"] = _id
        return list(coll.find(data_dict, field_dict).sort(sort_field, sort_type).limit(limit=limit))

    def count(self, table_name, data_dict={}):
        """
        计算当前集合数量
        :param table_name:
        :param data_dict:
        :return:
        """
        coll = self.db[table_name]
        _id = data_dict.get("id", "")
        if _id:
            data_dict["_id"] = _id
        return coll.count_documents(data_dict)


if __name__ == "__main__":
    username = 'admin'  # 用户名
    password = '123456'  # 密码
    host = '127.0.0.1'
    port = 27017
    dbname = 'dw'
    conn_url = f'mongodb://{username}:{password}@{host}:{port}/{dbname}?authSource=admin'
    # 设置读取来时间的时区

    mongo = MongoHelper(conn_url=conn_url)

    table_name = "table_name "

    # 获取时间大于'2022-01-14 10:59:06的值
    date = datetime.strptime('2022-01-14 10:59:06', '%Y-%m-%d %H:%M:%S')


    class UTC(tzinfo):
        """UTC"""

        def __init__(self, offset=0):
            self._offset = offset

        def utcoffset(self, dt):
            return timedelta(hours=self._offset)

        def tzname(self, dt):
            return "UTC +%s" % self._offset

        def dst(self, dt):
            return timedelta(hours=self._offset)


    year = date.year
    month = date.month
    day = date.day
    hour = date.hour
    minute = date.minute
    second = date.second
    create_time = datetime(year, date.month, date.day, date.hour, minute, second, 000000, tzinfo=UTC(8))
    documents = mongo.get_all(table_name, data_dict={"create_time": {"$gte": create_time}},
                              field_dict={}, limit=10)

    for doc in documents:
        doc['create_time'] = doc['create_time'].strftime('%Y-%m-%d %H:%M:%S')
        doc['update_time'] = doc['update_time'].strftime('%Y-%m-%d %H:%M:%S')
        print(doc)