在这一章中，我们先以一个简单例子来演示下mongodb数据的存储。
环境准备
mongodb服务端下载地址:
www.mongodb.com/download-ce…
robomongo客户端下载地址:
robomongo.org/download
连接配置
详细配置信息如下：
单条记录的写入
执行mongodb指令如下:
db.test.save({
"city_id" : "298",
"city_name" : "阿坝",
"lat" : 31.9055115772665,
"lng" : 102.23141546175
})
或者
db.test.insert({
"city_id" : "298",
"city_name" : "阿坝",
"lat" : 31.9055115772665,
"lng" : 102.23141546175
})
在指定_id主键的情况下,insert如果插入的主键已经存在,会抛出异常:
(E11000 duplicate key error collection: logs.test index: id dup key: { : "298" }
save则会更新库中对应该_id主键的数据
执行结果如下:
{
"_id" : ObjectId("5e1d8e64876551cd96cb576d"),
"city_id" : "298",
"city_name" : "阿坝",
"lat" : 31.9055115772665,
"lng" : 102.23141546175
}
在未指定_id主键情况下,mongodb会自动生成ObjectId类型主键
多条记录的写入
执行mongodb指令:
db.test.insertMany([{
"city_id" : "299",
"city_name" : "阿坝1",
"lat" : 31.9055115772665,
"lng" : 102.23141546175
},{
"city_id" : "300",
"city_name" : "阿坝2",
"lat" : 31.9055115772665,
"lng" : 102.23141546175
}])
返回结果:
{
"acknowledged" : true,
"insertedIds" : [
ObjectId("5e1d9397876551cd96cb576f"),
ObjectId("5e1d9397876551cd96cb5770")
]
}
如果写入的多条记录中存在_id主键,同时存在重复主键,则重复记录之后的记录会写入失败。
如需解决如上问题，可以使用python脚本功能实现:
from pymongo import UpdateOne
collection_test = mongo_util.get_clllection('test', 'test')
list_result = [{
"_id" : "299",
"city_id" : "299",
"city_name" : "阿坝1",
"lat" : 31.9055115772665,
"lng" : 102.23141546175
},{
"_id" : "301",
"city_id" : "301",
"city_name" : "阿坝3",
"lat" : 31.9055115772665,
"lng" : 102.23141546175
}]
write_list = []
for res in list_result:
write_list.append(UpdateOne({'_id': res['_id']}, {'$set': res}, upsert=True))
collection_test.bulk_write(write_result, ordered=False)
如上，如果批量写入的数据中主键_id已经存在了,则会执行更行命令,否则执行保存命令。
"""
mongo_util mongodb连接工具类
"""
from pymongo import MongoClient
connect_url = 'mongodb://root:123456@127.0.0.1:27017/admin'
client = MongoClient(connect_url, connect=False)
def get_collection(dbname, cllectionname):
"""
获取连接
:param dbname: 数据库名称
:param cllectionname: 表名称
:return:
"""
db = client[dbname]
collection_useraction = db[cllectionname]
return collection_useraction
