MongoDB pymongo模块 查询

查询

mongo_db 类似于 服务器命令行的db

我们可以db.user.find() 查询

find()

需要加上列表

import pymongo

mongo_client = pymongo.MongoClient(
    host='192.168.0.112',
    port=27017,
    username="admin",
    password=""
)

mongo_db = mongo_client["db1"]
# 查询
res = mongo_db.user.find()
res = list(res)
print(res)

返回结果，和服务器一样的

[
    {'_id': ObjectId('5ca7a4b0219efd687462f965'), 'id': 1.0, 'name': 'jack', 'age': 73.0},
    {'_id': ObjectId('5ca7a4b7219efd687462f966'), 'id': 2.0, 'name': 'mike', 'age': 84.0, 'gender': '男'},
    {'_id': ObjectId('5ca7a4c4219efd687462f967'), 'id': 3.0, 'name': 'peter', 'age': 21.0},
    {'_id': ObjectId('5ca7a4c4219efd687462f968'), 'id': 4.0, 'name': 'xiaogang', 'age': 34.0, 'hobby': ['篮球']},
    {'_id': ObjectId('5ca7a4c4219efd687462f969'), 'id': 5.0, 'name': 'ben', 'age': 24.0},
    {'_id': ObjectId('5ca7a505219efd687462f96a'), 'id': 6.0, 'name': 'Mary', 'age': 84.0, 'gender': '男'}
]

find_one()方法：

import pymongo

# 生成pymongo对象,传入连接服务器相关参数 ip 端口
mongo_client = pymongo.MongoClient(
    host='192.168.0.112',
    port=27017,
    username="admin",
    password=""
)

# 选择连接的数据库
mongo_db = mongo_client["db1"]
# 查询
res = mongo_db.user.find_one()
print(res)

和findOne效果一样，返回第一条数据

{'_id': ObjectId('5ca7a4b0219efd687462f965'), 'id': 1.0, 'name': 'jack', 'age': 73.0}

是一个字典可以取

import pymongo

# 生成pymongo对象,传入连接服务器相关参数 ip 端口
mongo_client = pymongo.MongoClient(
    host='192.168.0.112',
    port=27017,
    username="admin",
    password=""
)

# 选择连接的数据库
mongo_db = mongo_client["db1"]
# 查询
res = mongo_db.user.find_one()
print(res.get("_id"))

# 5ca7a4b0219efd687462f965

循环对象，循环比加list好，因为res是生成器，效率高

import pymongo

mongo_client = pymongo.MongoClient(
    host='192.168.0.112',
    port=27017,
    username="admin",
    password=""
)

mongo_db = mongo_client["db1"]
# 查询
res = mongo_db.user.find()
print(res)

for i in res:
    print(i)

是一个生成器，

<pymongo.cursor.Cursor object at 0x0000000002EC2DA0>

{'_id': ObjectId('5ca7a4b0219efd687462f965'), 'id': 1.0, 'name': 'jack', 'age': 73.0}
{'_id': ObjectId('5ca7a4b7219efd687462f966'), 'id': 2.0, 'name': 'mike', 'age': 84.0, 'gender': '男'}
{'_id': ObjectId('5ca7a4c4219efd687462f967'), 'id': 3.0, 'name': 'peter', 'age': 21.0}
{'_id': ObjectId('5ca7a4c4219efd687462f968'), 'id': 4.0, 'name': 'xiaogang', 'age': 34.0, 'hobby': ['篮球']}
{'_id': ObjectId('5ca7a4c4219efd687462f969'), 'id': 5.0, 'name': 'ben', 'age': 24.0}
{'_id': ObjectId('5ca7a505219efd687462f96a'), 'id': 6.0, 'name': 'Mary', 'age': 84.0, 'gender': '男'}

条件查询

import pymongo

mongo_client = pymongo.MongoClient(
    host='192.168.0.112',
    port=27017,
    username="admin",
    password=""
)

mongo_db = mongo_client["db1"]
# 条件查询
res = mongo_db.user.find_one({"age":34})
print(res)

# {'_id': ObjectId('5ca7a4c4219efd687462f968'), 'id': 4.0, 'name': 'xiaogang', 'age': 34.0, 'hobby': ['篮球']}