Python编程：mongodb的基本增删改查操作
# -*- coding: utf-8 -*- # @File : pymongo_demo.py # @Date : 2018-06-02 # @Author : Peng Shiyu import pymongo
1、创建MongoDB的连接对象
# client = pymongo.MongoClient(host="localhost", port=27017) client = pymongo.MongoClient('mongodb://localhost:27017/')
2、指定数据库
# db = client["mydemo"] db = client.mydemo
3、指定集合Collection对象
# collection = db["students"] collection = db.students
4、插入数据
# 一条数据 student = { 'id': '20170101', 'name': '小明', 'age': 22, 'gender': '男性' } # result = collection.insert(student) result = collection.insert_one(student) print(result) # <pymongo.results.InsertOneResult object at 0x1034e08c8> print(result.inserted_id) # 5b1205b2d7696c4230dd9456 # 多条数据 student1 = { 'id': '20170101', 'name': 'Jordan', 'age': 20, 'gender': 'male' } student2 = { 'id': '20170202', 'name': 'Mike', 'age': 21, 'gender': 'male' } # # # result = collection.insert([student1, student2]) result = collection.insert_many([student1, student2]) print(result) # <pymongo.results.InsertManyResult object at 0x1034e0748> print(result.inserted_ids) # # [ObjectId('5b1205b2d7696c4230dd9457'), ObjectId('5b1205b2d7696c4230dd9458')]
5、查询数据库
# 查询一条数据 result = collection.find_one({"name": "Mike"}) print(type(result)) # <class 'dict'> print(result) # {'_id': ObjectId('5b1204a3d7696c41c083d21e'), # 'id': '20170202', 'name': 'Mike', 'age': 21, 'gender': 'male'} # 通过_id属性来查询， 不存在则返回None from bson.objectid import ObjectId result = collection.find_one({'_id': ObjectId('5b1204a3d7696c41c083d21e')}) print(result) # {'_id': ObjectId('5b1204a3d7696c41c083d21e'), # 'id': '20170202', 'name': 'Mike', 'age': 21, 'gender': 'male'} # 查询多条数据, 返回一个生成器 results = collection.find({"age": 21}) print(results) # <pymongo.cursor.Cursor object at 0x10133f160> for result in results: print(result) # {'_id': ObjectId('5b12055fd7696c4208deb74a'), # 'id': '20170202', 'name': 'Mike', 'age': 21, 'gender': 'male'} # 条件查询 results = collection.find({"age": {"$gt": 20}}) for result in results: print(result) # {'_id': ObjectId('5b1209ccd7696c437c51d5bb'), # 'id': '20170101', 'name': '小明', 'age': 22, 'gender': '男性'} # {'_id': ObjectId('5b1209ccd7696c437c51d5bd'), # 'id': '20170202', 'name': 'Mike', 'age': 21, 'gender': 'male'} # 正则匹配查询 results = collection.find({"name": {"$regex": "^M.*"}}) for result in results: print(result) # {'_id': ObjectId('5b1209ccd7696c437c51d5bd'), # 'id': '20170202', 'name': 'Mike', 'age': 21, 'gender': 'male'} ## 转为list >>> db.collection.find() <pymongo.cursor.Cursor object at 0x108dabf50> >>> list(db.collection.find()) [ {'_id': ObjectId('5839b12eee86fb71849a0905'), 'name': 'Tom'} ]
比较符号
|
符号 |
表示 |
含义 |
示例 |
|
: |
= |
等于 |
{“age”: 20} |
|
$lt |
< |
小于 |
{“age”: {"$lt": 20}} |
|
$gt |
> |
大于 |
{“age”: {"$gt": 20}} |
|
$lte |
<= |
小于等于 |
{“age”: {"$lte": 20}} |
|
$gte |
>= |
大于等于 |
{“age”: {"$gte": 20}} |
|
$ne |
!= |
不等于 |
{“age”: {"$ne": 20}} |
|
$in |
in |
范围内 |
{“age”: {"$in": [20, 30]}} |
|
$nin |
not in |
不在范围内 |
{“age”: {"$nin": [20, 30]}} |
|
|
|
|
|
说明：
lt: less than
gt: great than
e: equal
功能符号
|
符号 |
含义 |
示例 |
示例说明 |
|
$regex |
匹配正则表达式 |
{“name”: {"$regex": “^M.*”}} |
name以M开头 |
|
$exists |
属性是否存在 |
{“name”: {"$exists": True}} |
name属性存在 |
|
$type |
类型判断 |
{“age”: {"$type": “int”}} |
age的类型为int |
|
$mod |
数字模操作 |
{“age”: {"$mod": [5, 0]}} |
年龄模5余0 |
|
$text |
文本查询 |
{“text”: {"$search": “Mike”}} |
text类型的属性中包含字符串Mike |
|
$where |
高级条件查询 |
{“name”: {"$where": “obj.age==obj.count”}} |
自身年龄等于自身数量 |
6、查询计数
count = collection.find().count() print(count) # 3
7、数据排序
# 升序pymongo.ASCENDING 降序pymongo.DESCENDING results = collection.find().sort("name", pymongo.ASCENDING) print([result["name"] for result in results]) # ['Jordan', 'Mike', '小明']
8、数据的偏移
results = collection.find().sort('name', pymongo.ASCENDING).skip(2) print([result['name'] for result in results]) # ['小明'] results = collection.find().sort('name', pymongo.ASCENDING).skip(1).limit(1) print([result['name'] for result in results]) # ['Mike'] # 数据库数量非常庞大的时候，不要使用大的偏移量 from bson.objectid import ObjectId results = collection.find({'_id': {'$gt': ObjectId('5b1209ccd7696c437c51d5bb')}}) print([result['name'] for result in results])
9、更新数据库
更新函数
update_one(filter, update, upsert=False, bypass_document_validation=False, collation=None, array_filters=None, session=None) update_many(filter, update, upsert=False, array_filters=None, bypass_document_validation=False, collation=None, session=None) # 过时了 update(spec, document, upsert=False, manipulate=False, multi=False, check_keys=True, **kwargs)
condition = {'name': 'Mike'} student = collection.find_one(condition) student['age'] = 25 # 全部用student字典替换 # result = collection.update(condition, student) # 只更新student字典内存在的字段 result = collection.update(condition, {'$set': student}) print(result) # {'n': 1, 'nModified': 1, 'ok': 1.0, 'updatedExisting': True} condition = {'name': 'Mike'} student = collection.find_one(condition) student['age'] = 26 result = collection.update_one(condition, {'$set': student}) print(result) # <pymongo.results.UpdateResult object at 0x1034de708> print(result.matched_count, result.modified_count) # 1 1 condition = {'age': {'$gt': 20}} result = collection.update_one(condition, {'$inc': {'age': 1}}) print(result) # <pymongo.results.UpdateResult object at 0x1034e8588> print(result.matched_count, result.modified_count) # 1 1
10、数据删除
result = collection.remove({'name': 'Jordan'}) print(result) # 删除一条 result = collection.delete_one({'name': 'Kevin'}) print(result) print(result.deleted_count) result = collection.delete_many({'age': {'$lt': 25}}) print(result.deleted_count) # 删除多条 result = collection.delete_many({'name': 'Kevin'})
官方文档：
http://api.mongodb.com/python/current/api/pymongo/collection.html
多条件查询
db.getCollection('table').find({"$and": [{"detail": {"$ne": null}}, {"detail": {"$ne": true}}]})