方式1：简写

connect('students')

>>> from mongoengine import connect

>>> connect('students')

MongoClient(host=['localhost:27017'], document_class=dict, tz_aware=False, connect=True, read_preference=Primary())

方式2：指定端口和地址

connect('students',host='192.168.3.96',port=)

方式3：使用URI

connect('students',host='mongodb://localhost/students')

#coding:utf-8

from mongoengine import connect, Document, EmbeddedDocument, DynamicDocument, StringField, IntField,\

FloatField, ListField, EmbeddedDocumentField

connect('students')

SEX_CHICES = (

    ('male','男'),

    ('female','女')

)

class Grade(EmbeddedDocument):

    ''' 成绩 '''

    name = StringField(required=True)

    score = FloatField(required=True)

# class Student(Document):

class Student(DynamicDocument):

    '''学生'''

    name = StringField(max_length=32, required=True)

    age = IntField(required=True)

    sex = StringField(choices=SEX_CHICES, required=True)

    grade = FloatField()

    address = StringField()

    grades = ListField(EmbeddedDocumentField(Grade))

    meta = {

        'collection': 'students',

        # 排序功能，按照分数倒序

        'ordering':['-grade']

    }

class TestMongoEngine(object):

    def add_one(self):

        '''添加一条数据到数据库'''

        yuwen = Grade(

            name = '语文',

            score = 90)

        shuxue = Grade(

            name = '数学',

            score = 100)

        stu_obj = Student(

            name = '张三丰',

            age = 15,

            grades = [yuwen, shuxue],

            sex = 'male'

        )

        # 直接添加remark字段是无法添加成功的，需要引入动态添加字段的方法DynamicDocument
　　　　　

        stu_obj.remark = 'remark'

        stu_obj.save()

        return stu_obj

    def get_one(self):

        ''' 获取单条数据 '''

        return Student.objects.first()

    def get_more(self):

        ''' 获取多条数据 '''

        # return Student.objects

        return Student.objects.all()

    def get_one_from_oid(self, oid):

        ''' 查询指定id的数据 '''

        return Student.objects.filter(id=oid).first()

    def update(self):

        ''' 修改数据 '''

        # 修改一条数据

        # res = Student.objects.filter(sex='male').update_one(inc__age=1)

        # return res

        # 修改多条数据

        res = Student.objects.filter(sex = 'male').update(inc__age=10)

        return res

    def delete(self):

        ''' 删除数据 '''

        # 删除一条数据

        # res = Student.objects.filter(sex='male').first().delete()

        # return res

        # 删除多条数据

        res = Student.objects.filter(gender='male').delete()

def main():

    en = TestMongoEngine()

    # en.add_one()

    # res = en.get_one()

    # print(res.name)

    # rows = en.get_more()

    # for row in rows:

    #     print(row.name)

    # res = en.get_one_from_oid('5a9df2e48a86b467d4a2c44f')

    # print(res.name)

    # res = en.update()

    # print(res)

    res = en.delete()

    print(res)

if __name__ == "__main__":

    main()