django开发-mongodb的配置与使用

摘要：今天整理了一下在项目中如何使用环境如下第一步在中配置和配置如下可以同时使用和数据库引擎你要存储数据的库名，事先要创建之数据库用户名密码主机数据库使用的端口连接中数据库名称为的数据库第二步向中插入数据插入类型数据插入数据格式为插入含有的数据用

今天整理了一下在django项目中如何使用mongodb, 环境如下：
ubuntu18.04, django2.0.5, drf3.9, mongoengine0.16

第一步：在settings.py中配置mongodb和mysql,配置如下(可以同时使用mysql和mongodb):

DATABASES = {
    "default": {
        "ENGINE": "django.db.backends.mysql",   # 数据库引擎
        "NAME": "django_test2",                  # 你要存储数据的库名，事先要创建之
        "USER": "root",                         # 数据库用户名
        "PASSWORD": "wyzane",                     # 密码
        "HOST": "localhost",                    # 主机
        "PORT": "3306",                         # 数据库使用的端口
    },
    "mongotest": {
        "ENGINE": None,
    }
}

import mongoengine
# 连接mongodb中数据库名称为mongotest5的数据库
conn = mongoengine.connect("mongotest")

第二步：向mongodb中插入数据
1.插入json类型数据

models.py:
    import mongoengine
    class StudentModel(mongoengine.Document):
        name = mongoengine.StringField(max_length=32)
        age = mongoengine.IntField()
        password = mongoengine.StringField(max_length=32)

views.py:
    from rest_framework.views import APIView
    class FirstMongoView(APIView):
        def post(self, request):
            name = request.data["name"]
            age = request.data["age"]
            password = request.data["password"]
            StudentModel.objects.create(name=name, age=age, password=password)
            return Response(dict(msg="OK", code=10000))

插入数据格式为:

{
    "name": "nihao",
    "age": 18,
    "password": "123456"
}

2.插入含有list的json数据

models.py:
    import mongoengine
    class Student2Model(mongoengine.Document):
        name = mongoengine.StringField(max_length=32)
        # 用于存储list类型的数据
        score = mongoengine.ListField()

views.py:
    from rest_framework.views import APIView
    class FirstMongo2View(APIView):
        def post(self, request):
            name = request.data["name"]
            score = request.data["score"]
            Student2Model.objects.create(name=name, score=score)
            return Response(dict(msg="OK", code=10000))

插入数据格式为：

{
     "name": "test",
     "score": [12, 13]
}

3.插入含有dict和list的复杂json数据

models.py:
    import mongoengine
    class Student3Model(mongoengine.Document):
        name = mongoengine.StringField(max_length=32)
        # DictField用于存储字典类型的数据
        score = mongoengine.DictField()
views.py:
    from rest_framework.views import APIView
    class FirstMongo3View(APIView):
        def post(self, request):
            name = request.data["name"]
            score = request.data["score"]
            Student3Model.objects.create(name=name, score=score)
            return Response(dict(msg="OK", code=10000))

插入数据格式为:

{
    "name": "test",
    "score": {"xiaoming": 12, "xiaoli": 13}
}
或者:
{
    "name": "test",
    "score": {"xiaoming": 12, "xiaoli": {"xiaozhao": 14}}
}
或者:
{
"name": "test",
"score": {"xiaoming": 12, "xiaoli": {"xiaozhao": {"xiaoliu": 12, "xiaojian": 18}}}
}
或者:
{
"name": "test",
"score": {"xiaoming": 12, "xiaoli": {"xiaozhao": {"xiaoliu": 12, "xiaojian": [12,13,14]}}}
}

第三步：查询mongodb中的数据
1.查询并序列化复杂json数据

serializers.py:
    class StudentSerializer(serializers.Serializer):
        name = serializers.CharField()
        score = serializers.DictField()  # 序列化复杂的json数据
        # DictField与EmbeddedDocumentField类似，但是比EmbeddedDocumentField更灵活
views.py:
    class FirstMongo4View(APIView):
        def get(self, request):
            student_info = Student3Model.objects.all()
            # 增加过滤条件
            # student_info = Student3Model.objects.filter(name="test1")
            ser = StudentSerializer(instance=student_info, many=True)
            return Response(dict(msg="OK", code="10000", data=ser.data))

2.序列化mongodb中含有嵌套关系的两个document

models.py:
    class AuthorModel(mongoengine.EmbeddedDocument):
        author_name = mongoengine.StringField(max_length=32)
        age = mongoengine.IntField()


    class BookModel(mongoengine.Document):
        book_name = mongoengine.StringField(max_length=64)
        publish = mongoengine.DateTimeField(default=datetime.datetime.utcnow())
        words = mongoengine.IntField()
        author = mongoengine.EmbeddedDocumentField(AuthorModel)

serializers.py: 序列化时注意与rest_framework的序列化中DictField()的区别
    from rest_framework_mongoengine import serializers as s1
    class AuthorSerializer(s1.DocumentSerializer):  
        # DocumentSerializer继承自drf中的ModelSerializer，用于代替ModelSerializer序列化mongodb中的document.
        # 具体可以到官网上查看
        class Meta:
            model = AuthorModel
            fields = ("author_name", "age")


    class BookSerializer(s1.DocumentSerializer):
        author = AuthorSerializer()

        class Meta:
            model = BookModel
            fields = ("book_name", "publish", "words", "author")

    AuthorSerializer还可以这样写:
    class AuthorSerializer(s1.EmbeddedDocumentSerializer):
        # EmbeddedDocumentSerializer继承了DocumentSerializer
        class Meta:
            model = AuthorModel
            fields = ("author_name", "age")

views.py:
    class BookView(APIView):
        def get(self, request):
            """
            查询数据
            :param request:
            :return:
            """
            books = BookModel.objects.all()
            ser = BookSerializer(instance=books, many=True)
            return Response(dict(msg="OK", code="10000", data=ser.data))

序列化mongodb中相关联的两个表时，如果序列化器继承自rest_framework中的Serializer和ModelSerializer，会抛出如下异常：

Django serialization to JSON error: "MetaDict" object has no attribute "concrete_model"

此时，序列化器需要继承自rest_framework_mongoengine的类，具体可以查看官网：
http://umutbozkurt.github.io/...

今天就聊到这里，如有问题，欢迎交流。