Python操做MongoDB文檔數據庫

時間 2019-12-08

原文原文鏈接

1.Pymongo 安裝

安裝pymongo：

pip install pymongo

PyMongo是驅動程序，使python程序可以使用Mongodb數據庫，使用python編寫而成；

2.Pymongo 方法

one_insert()：插入一條記錄；
insert()：插入多條記錄；
find_one()：查詢一條記錄，不帶任何參數返回第一條記錄，帶參數則按條件查找返回；
find()：查詢多條記錄，不帶參數返回全部記錄，帶參數按條件查找返回；
count()：查看記錄總數；
create_index()：建立索引；
update_one()：更新匹配到的第一條數據；
update()：更新匹配到的全部數據；
remove()：刪除記錄，不帶參表示刪除所有記錄，帶參則表示按條件刪除；
delete_one()：刪除單條記錄；
delete_many()：刪除多條記錄；

3.Pymongo 中的操做

查看數據庫

from pymongo import MongoClient

connect = MongoClient(host='localhost', port=27017, username="root", password="123456")
connect = MongoClient('mongodb://localhost:27017/', username="root", password="123456")

print(connect.list_database_names())

獲取數據庫實例

test_db = connect['test']

獲取collection實例

collection = test_db['students']

插入一行document, 查詢一行document，取出一行document的值

from pymongo import MongoClient
from datetime import datetime

connect = MongoClient(host='localhost', port=27017, username="root", password="123456",)
# 獲取db
test_db = connect['test']
# 獲取collection
collection = test_db['students']
# 構建document
document = {"author": "Mike",  "text": "My first blog post!", "tags": ["mongodb", "python", "pymongo"], "date": datetime.now()}
# 插入document
one_insert = collection.insert_one(document=document)
print(one_insert.inserted_id)

# 經過條件過濾出一條document
one_result = collection.find_one({"author": "Mike"})
# 解析document字段
print(one_result, type(one_result))
print(one_result['_id'])
print(one_result['author'])

注意：若是須要經過id查詢一行document，須要將id包裝爲ObjectId類的實例對象
from bson.objectid import ObjectId
collection.find_one({'_id': ObjectId('5c2b18dedea5818bbd73b94c')})

插入多行documents, 查詢多行document，查看collections有多少行document

from pymongo import MongoClient
from datetime import datetime
connect = MongoClient(host='localhost', port=27017, username="root", password="123456",)

# 獲取db
test_db = connect['test']

# 獲取collection
collection = test_db['students']
documents = [{"author": "Mike","text": "Another post!","tags": ["bulk", "insert"], "date": datetime(2009, 11, 12, 11, 14)},
{"author": "Eliot", "title": "MongoDB is fun", "text": "and pretty easy too!", "date": datetime(2009, 11, 10, 10, 45)}]
collection.insert_many(documents=documents)

# 經過條件過濾出多條document
documents = collection.find({"author": "Mike"})

# 解析document字段
print(documents, type(documents))
print('*'*300)
for document in documents:
    print(document)
print('*'*300)
result = collection.count_documents({'author': 'Mike'})
print(result)

範圍比較查詢

from pymongo import MongoClient
from datetime import datetime

connect = MongoClient(host='localhost', port=27017, username="root", password="123456",)

# 獲取db
test_db = connect['test']

# 獲取collection
collection = test_db['students']

# 經過條件過濾時間小於datetime(2019, 1,1,15,40,3) 的document
documents = collection.find({"date": {"$lt": datetime(2019, 1,1,15,40,3)}}).sort('date')

# 解析document字段
print(documents, type(documents))
print('*'*300)
for document in documents:
    print(document)

建立索引

from pymongo import MongoClient
import pymongo
from datetime import datetime

connect = MongoClient(host='localhost', port=27017, username="root", password="123456",)
# 獲取db
test_db = connect['test']
# 獲取collection
collection = test_db['students']
# 建立字段索引
collection.create_index(keys=[("name", pymongo.DESCENDING)], unique=True)
# 查詢索引
result = sorted(list(collection.index_information()))
print(result)

document修改

from pymongo import MongoClient
connect = MongoClient(host='localhost', port=27017, username="root", password="123456",)

# 獲取db
test_db = connect['test']

# 獲取collection
collection = test_db['students']
result = collection.update({'name': 'robby'}, {'$set': {"name": "Petter"}})
print(result)
注意：還有update_many()方法

document刪除

from pymongo import MongoClient
connect = MongoClient(host='localhost', port=27017, username="root", password="123456",)

# 獲取db
test_db = connect['test']

# 獲取collection
collection = test_db['students']
result = collection.delete_one({'name': 'Petter'})
print(result.deleted_count)
注意：還有delete_many()方法

4.MongoDB ODM 詳解

MongoDB ODM 與 Django ORM使用方法相似；
MongoEngine是一個對象文檔映射器，用Python編寫，用於處理MongoDB；
MongoEngine提供的抽象是基於類的，建立的全部模型都是類；

# 安裝mongoengine
pip install mongoengine

mongoengine使用的字段類型

BinaryField
BooleanField
ComplexDateTimeField
DateTimeField
DecimalField
DictField
DynamicField
EmailField
EmbeddedDocumentField
EmbeddedDocumentListField
FileField
FloatField
GenericEmbeddedDocumentField
GenericReferenceField
GenericLazyReferenceField
GeoPointField
ImageField
IntField
ListField:能夠將自定義的文檔類型嵌套
MapField
ObjectIdField
ReferenceField
LazyReferenceField
SequenceField
SortedListField
StringField
URLField
UUIDField
PointField
LineStringField
PolygonField
MultiPointField
MultiLineStringField
MultiPolygonField

5.使用mongoengine建立數據庫鏈接

from mongoengine import connect

conn = connect(db='test', host='localhost', port=27017, username='root', password='123456', authentication_source='admin')
print(conn)

connect（db = None，alias ='default'，** kwargs ）；html

db：要使用的數據庫的名稱，以便與connect兼容；
host ：要鏈接的mongod實例的主機名；
port ：運行mongod實例的端口；
username：用於進行身份驗證的用戶名；
password：用於進行身份驗證的密碼；
authentication_source ：要進行身份驗證的數據庫；

構建文檔模型，插入數據python

from mongoengine import connect, \
                        Document, \
                        StringField,\
                        IntField, \
                        FloatField,\
                        ListField, \
                        EmbeddedDocumentField,\
                        DateTimeField, \
                        EmbeddedDocument
from datetime import datetime

# 嵌套文檔
class Score(EmbeddedDocument):
    name = StringField(max_length=50, required=True)
    value = FloatField(required=True)

class Students(Document):
    choice =  (('F', 'female'),
               ('M', 'male'),)
    name = StringField(max_length=100, required=True, unique=True)
    age = IntField(required=True)
    hobby = StringField(max_length=100, required=True, )
    gender = StringField(choices=choice, required=True)
    # 這裏使用到了嵌套文檔，這個列表中的每個元素都是一個字典，所以使用嵌套類型的字段
    score = ListField(EmbeddedDocumentField(Score))
    time = DateTimeField(default=datetime.now())

if __name__ == '__main__':
    connect(db='test', host='localhost', port=27017, username='root', password='123456', authentication_source='admin')
    math_score = Score(name='math', value=94)
    chinese_score = Score(name='chinese', value=100)
    python_score = Score(name='python', value=99)

    for i in range(10):
        students = Students(name='robby{}'.format(i), age=int('{}'.format(i)), hobby='read', gender='M', score=[math_score, chinese_score, python_score])
        students.save()

查詢數據mongodb

from mongoengine import connect, \
                        Document, \
                        StringField,\
                        IntField, \
                        FloatField,\
                        ListField, \
                        EmbeddedDocumentField,\
                        DateTimeField, \
                        EmbeddedDocument
from datetime import datetime

# 嵌套文檔
class Score(EmbeddedDocument):
    name = StringField(max_length=50, required=True)
    value = FloatField(required=True)

class Students(Document):
    choice =  (('F', 'female'),
               ('M', 'male'),)

    name = StringField(max_length=100, required=True, unique=True)
    age = IntField(required=True)
    hobby = StringField(max_length=100, required=True, )
    gender = StringField(choices=choice, required=True)
    # 這裏使用到了嵌套文檔，這個列表中的每個元素都是一個字典，所以使用嵌套類型的字段
    score = ListField(EmbeddedDocumentField(Score))
    time = DateTimeField(default=datetime.now())

if __name__ == '__main__':
    connect(db='test', host='localhost', port=27017, username='root', password='123456', authentication_source='admin')

    first_document = Students.objects.first()

    all_document = Students.objects.all()

    # 若是隻有一條，也能夠使用get
    specific_document = Students.objects.filter(name='robby3')

    print(first_document.name, first_document.age, first_document.time)

    for document in all_document:
        print(document.name)

    for document in specific_document:
        print(document.name, document.age)

修改、更新、刪除數據數據庫

from mongoengine import connect, \
                        Document, \
                        StringField,\
                        IntField, \
                        FloatField,\
                        ListField, \
                        EmbeddedDocumentField,\
                        DateTimeField, \
                        EmbeddedDocument
from datetime import datetime

# 嵌套文檔
class Score(EmbeddedDocument):
    name = StringField(max_length=50, required=True)
    value = FloatField(required=True)

class Students(Document):
    choice =  (('F', 'female'),
               ('M', 'male'),)

    name = StringField(max_length=100, required=True, unique=True)
    age = IntField(required=True)
    hobby = StringField(max_length=100, required=True, )
    gender = StringField(choices=choice, required=True)
    # 這裏使用到了嵌套文檔，這個列表中的每個元素都是一個字典，所以使用嵌套類型的字段
    score = ListField(EmbeddedDocumentField(Score))
    time = DateTimeField(default=datetime.now())

if __name__ == '__main__':
    connect(db='test', host='localhost', port=27017, username='root', password='123456', authentication_source='admin')

    specific_document = Students.objects.filter(name='robby3')
    specific_document.update(set__age=100)
    specific_document.update_one(set__age=100)

    for document in specific_document:
        document.name = 'ROBBY100'
        document.save()

    for document in specific_document:
        document.delete()