復習
"""
1、解析模塊：全局局部配置
REST_FRAMEWORK = {
# 全局解析類配置
'DEFAULT_PARSER_CLASSES': [
'rest_framework.parsers.JSONParser',
'rest_framework.parsers.FormParser',
'rest_framework.parsers.MultiPartParser'
],
}
form rest_framework.parsers import JSONParser, FormParser
class User(APIView):
parser_classes = [JSONParser, FormParser]
def get():
pass
2、異常模塊
REST_FRAMEWORK = {
# 全局配置異常模塊
'EXCEPTION_HANDLER': 'api.exception.exception_handler',
}
def exception_handler(exc, context):
response = drf views 中的 exception_handler 先處理
if response is None:
通過context，exc記錄詳細的異常信息
自己自定義響應對象
return Response({
'detail': '服務器錯誤'
}, status=status.HTTP_500_INTERNAL_SERVER_ERROR, exception=True)
return response
3、響應模塊
Response(data, status, headers, content_type, exception)
4、Serializer序列化模塊
序列化
ser：
1）設置需要返回給前台 那些model類有對應的 字段，不需要返回的就不用設置了
2）設置方法字段，字段名可以隨意，字段值有 get_字段名 提供，來完成一些需要處理在返回的數據
view：
1）從數據庫中將要序列化給前台的model對象，或是對個model對象查詢出來
user_obj = models.User.objects.get(pk=pk) 或者
user_obj_list = models.User.objects.all()
2）將對象交給序列化處理，產生序列化對象，如果序列化的是多個數據，要設置many=True
user_ser = serializers.UserSerializer(user_obj) 或者
user_ser = serializers.UserSerializer(user_obj_list, many=True)
3）序列化 對象.data 就是可以返回給前台的序列化數據
return Response({
'status': 0,
'msg': 0,
'results': user_ser.data
})
反序列化
ser：
1）設置必填與選填序列化字段，設置校驗規則
2）為需要額外校驗的字段提供局部鈎子函數，如果該字段不入庫，且不參與全局鈎子校驗，可以將值取出校驗
3）為有聯合關系的字段們提供全局鈎子函數，如果某些字段不入庫，可以將值取出校驗
4）重寫create方法，完成校驗通過的數據入庫工作，得到新增的對象
view：
"""
課程准備
配置：settings.py
INSTALLED_APPS = [
# ...
'rest_framework',
]
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': 'dg_proj',
'USER': 'root',
'PASSWORD': '123',
}
}
"""
任何__init__文件
import pymysql
pymysql.install_as_MySQLdb()
"""
LANGUAGE_CODE = 'zh-hans'
TIME_ZONE = 'Asia/Shanghai'
USE_I18N = True
USE_L10N = True
USE_TZ = False
MEDIA_URL = '/media/'
MEDIA_ROOT = os.path.join(BASE_DIR, 'media')
路由
# 主
from django.conf.urls import url, include
from django.contrib import admin
from django.views.static import serve
from django.conf import settings
urlpatterns = [
url(r'^admin/', admin.site.urls),
url(r'^api/', include('api.urls')),
url(r'^media/(?P<path>.*)', serve, {'document_root': settings.MEDIA_ROOT}),
]
# 子
from django.conf.urls import url
from . import views
urlpatterns = [
]
多表設計
"""
Book表：name、price、img、authors、publish、is_delete、create_time
Publish表：name、address、is_delete、create_time
Author表：name、age、is_delete、create_time
AuthorDetail表：mobile, author、is_delete、create_time
BaseModel基表
is_delete、create_time
上面四表繼承基表，可以繼承兩個字段
"""
基表
class BaseModel(models.Model):
is_delete = models.BooleanField(default=False)
create_time = models.DateTimeField(auto_now_add=True)
# 設置 abstract = True 來聲明基表，作為基表的Model不能在數據庫中形成對應的表
class Meta:
abstract = True
多表關系斷關聯
知識點（重點）
"""
1、外鍵位置：
一對多 - 外鍵放多的一方
一對一 - 從邏輯正反向考慮，如作者表與作者詳情表，作者刪除級聯刪除詳情，詳情刪除作者依舊存在，所以建議外鍵在詳情表中
多對多 - 外鍵在關系表中
2、ORM正向反向連表查找：
正向：通過外鍵字段 eg: author_detial_obj.author
反向：通過related_name的值 eg：author_obj.detail
注：依賴代碼見下方
3、連表操作關系：
1）作者刪除，詳情級聯 - on_delete=models.CASCADE
2）作者刪除，詳情置空 - null=True, on_delete=models.SET_NULL
3）作者刪除，詳情重置 - default=0, on_delete=models.SET_DEFAULT
4）作者刪除，詳情不動 - on_delete=models.DO_NOTHING
注：拿作者與作者詳情表舉例
4、外鍵關聯字段的參數 - 如何實現 斷關聯、目前表間操作關系、方向查詢字段
i）作者詳情表中的
author = models.OneToOneField(
to='Author',
related_name='detail',
db_constraint=False,
on_delete=models.CASCADE
)
ii）圖書表中的
publish = models.ForeignKey(
to='Publish',
related_name='books',
db_constraint=False,
on_delete=models.DO_NOTHING,
)
authors = models.ManyToManyField(
to='Author'
related_name='books',
db_constraint=False,
)
注：ManyToManyField不能設置on_delete，OneToOneField、ForeignKey必須設置on_delete（django1.x系統默認級聯，但是django2.x必須手動明確）
"""
model類
from django.db import models
# 圖書管理系統：Book、Author、AuthorDetail、Publish
"""
Book表: name、price、img、authors、publish、is_delete、create_time
Publish表: name、address、is_delete、create_time
Author表: name、age、is_delete、create_time
AuthorDetail表: mobile, author、is_delete、create_time
"""
# 1) 基表
class BaseModel(models.Model):
is_delete = models.BooleanField(default=False)
create_time = models.DateTimeField(auto_now_add=True)
# 作為基表的Model不能在數據庫中形成對應的表，設置 abstract = True
class Meta:
abstract = True
class Book(BaseModel):
"""name、price、img、authors、publish、is_delete、create_time"""
name = models.CharField(max_length=64)
price = models.DecimalField(max_digits=5, decimal_places=2)
img = models.ImageField(upload_to='img', default='img/default.jpg')
publish = models.ForeignKey(
to='Publish',
db_constraint=False, # 斷關聯
related_name='books', # 反向查詢字段：publish_obj.books 就能訪問所有出版的書
on_delete=models.DO_NOTHING, # 設置連表操作關系
)
authors = models.ManyToManyField(
to='Author',
db_constraint=False,
related_name='books'
)
# 序列化插拔式屬性 - 完成自定義字段名完成連表查詢
@property
def publish_name(self):
return self.publish.name
@property
def author_list(self):
return self.authors.values('name', 'age', 'detail__mobile').all()
class Meta:
db_table = 'book'
verbose_name = '書籍'
verbose_name_plural = verbose_name
def __str__(self):
return self.name
class Publish(BaseModel):
"""name、address、is_delete、create_time"""
name = models.CharField(max_length=64)
address = models.CharField(max_length=64)
class Meta:
db_table = 'publish'
verbose_name = '出版社'
verbose_name_plural = verbose_name
def __str__(self):
return self.name
class Author(BaseModel):
"""name、age、is_delete、create_time"""
name = models.CharField(max_length=64)
age = models.IntegerField()
class Meta:
db_table = 'author'
verbose_name = '作者'
verbose_name_plural = verbose_name
def __str__(self):
return self.name
class AuthorDetail(BaseModel):
"""mobile, author、is_delete、create_time"""
mobile = models.CharField(max_length=11)
author = models.OneToOneField(
to='Author',
db_constraint=False,
related_name='detail',
on_delete=models.CASCADE,
)
class Meta:
db_table = 'author_detail'
verbose_name = '作者詳情'
verbose_name_plural = verbose_name
def __str__(self):
return '%s的詳情' % self.author.name
序列化
序列化層：api/serializers.py
from rest_framework.serializers import ModelSerializer, SerializerMethodField
from rest_framework.exceptions import ValidationError
from . import models
# 可以單獨作為Publish接口的序列化類，也可以作為Book序列化外鍵publish輔助的序列化組件
class PublishModelSerializer(ModelSerializer):
class Meta:
model = models.Publish
fields = ('name', 'address')
class BookModelSerializer(ModelSerializer):
# 了解: 該方式設置的序列化字段，必須在fields中聲明
# publish_address = SerializerMethodField()
# def get_publish_address(self, obj):
# return obj.publish.address
# 自定義連表深度 - 子序列化方式 - 該方式不能參與反序列化，使用在序列化反序列化共存時，不能書寫
publish = PublishModelSerializer()
class Meta:
# 序列化類關聯的model類
model = models.Book
# 參與序列化的字段
fields = ('name', 'price', 'img', 'author_list', 'publish')
# 了解知識點
# 所有字段
# fields = '__all__'
# 與fields不共存，exclude排除哪些字段
# exclude = ('id', 'is_delete', 'create_time')
# 自動連表深度
# depth = 1
視圖層：api/views.py
class Book(APIView):
def get(self, request, *args, **kwargs):
pk = kwargs.get('pk')
if pk:
try:
book_obj = models.Book.objects.get(pk=pk, is_delete=False)
book_data = serializers.BookModelSerializer(book_obj).data
except:
return Response({
'status': 1,
'msg': '書籍不存在'
})
else:
book_query = models.Book.objects.filter(is_delete=False).all()
book_data = serializers.BookModelSerializer(book_query, many=True).data
return Response({
'status': 0,
'msg': 'ok',
'results': book_data
})
路由層：api/urls.py
urlpatterns = [
url(r'^books/$', views.Book.as_view()),
url(r'^books/(?P<pk>.*)/$', views.Book.as_view()),
]
反序列化
序列化層：api/serializers.py
class BookModelDeserializer(ModelSerializer):
class Meta:
model = models.Book
fields = ('name', 'price', 'publish', 'authors')
# extra_kwargs 用來完成反序列化字段的 系統校驗規則
extra_kwargs = {
'name': {
'required': True,
'min_length': 1,
'error_messages': {
'required': '必填項',
'min_length': '太短',
}
}
}
# 局部鈎子
def validate_name(self, value):
# 書名不能包含 g 字符
if 'g' in value.lower():
raise ValidationError('該g書不能出版')
return value
# 全局鈎子
def validate(self, attrs):
publish = attrs.get('publish')
name = attrs.get('name')
if models.Book.objects.filter(name=name, publish=publish):
raise ValidationError({'book': '該書已存在'})
return attrs
# ModelSerializer類已經幫我們實現了 create 與 update 方法
視圖層：api/views.py
class Book(APIView):
def post(self, request, *args, **kwargs):
request_data = request.data
book_ser = serializers.BookModelDeserializer(data=request_data)
# raise_exception=True：當校驗失敗，馬上終止當前視圖方法，拋異常返回給前台
book_ser.is_valid(raise_exception=True)
book_obj = book_ser.save()
return Response({
'status': 0,
'msg': 'ok',
'results': serializers.BookModelSerializer(book_obj).data
})
路由層：api/urls.py
urlpatterns = [
url(r'^books/$', views.Book.as_view()),
url(r'^books/(?P<pk>.*)/$', views.Book.as_view()),
]
序列化與反序列化整合（重點）
序列化層：api/serializers.py
"""
1) fields中設置所有序列化與反序列化字段
2) extra_kwargs划分只序列化或只反序列化字段
write_only：只反序列化
read_only：只序列化
自定義字段默認只序列化(read_only)
3) 設置反序列化所需的 系統、局部鈎子、全局鈎子 等校驗規則
"""
class V2BookModelSerializer(ModelSerializer):
class Meta:
model = models.Book
fields = ('name', 'price', 'img', 'author_list', 'publish_name', 'publish', 'authors')
extra_kwargs = {
'name': {
'required': True,
'min_length': 1,
'error_messages': {
'required': '必填項',
'min_length': '太短',
}
},
'publish': {
'write_only': True
},
'authors': {
'write_only': True
},
'img': {
'read_only': True,
},
'author_list': {
'read_only': True,
},
'publish_name': {
'read_only': True,
}
}
def validate_name(self, value):
# 書名不能包含 g 字符
if 'g' in value.lower():
raise ValidationError('該g書不能出版')
return value
def validate(self, attrs):
publish = attrs.get('publish')
name = attrs.get('name')
if models.Book.objects.filter(name=name, publish=publish):
raise ValidationError({'book': '該書已存在'})
return attrs
視圖層：api/views.py
class V2Book(APIView):
# 單查：有pk
# 群查：無pk
def get(self, request, *args, **kwargs):
pk = kwargs.get('pk')
if pk:
try:
book_obj = models.Book.objects.get(pk=pk, is_delete=False)
book_data = serializers.V2BookModelSerializer(book_obj).data
except:
return Response({
'status': 1,
'msg': '書籍不存在'
})
else:
book_query = models.Book.objects.filter(is_delete=False).all()
book_data = serializers.V2BookModelSerializer(book_query, many=True).data
return Response({
'status': 0,
'msg': 'ok',
'results': book_data
})
# 單增：傳的數據是與model對應的字典
# 群增：傳的數據是 裝多個 model對應字典 的列表
def post(self, request, *args, **kwargs):
request_data = request.data
if isinstance(request_data, dict):
many = False
elif isinstance(request_data, list):
many = True
else:
return Response({
'status': 1,
'msg': '數據有誤',
})
book_ser = serializers.V2BookModelSerializer(data=request_data, many=many)
# 當校驗失敗，馬上終止當前視圖方法，拋異常返回給前台
book_ser.is_valid(raise_exception=True)
book_result = book_ser.save()
return Response({
'status': 0,
'msg': 'ok',
'results': serializers.V2BookModelSerializer(book_result, many=many).data
})
# 單刪：有pk
# 群刪：有pks | {"pks": [1, 2, 3]}
def delete(self, request, *args, **kwargs):
pk = kwargs.get('pk')
if pk:
pks = [pk]
else:
pks = request.data.get('pks')
if models.Book.objects.filter(pk__in=pks, is_delete=False).update(is_delete=True):
return Response({
'status': 0,
'msg': '刪除成功',
})
return Response({
'status': 1,
'msg': '刪除失敗',
})
路由層：api/urls.py
urlpatterns = [
url(r'^v2/books/$', views.V2Book.as_view()),
url(r'^v2/books/(?P<pk>.*)/$', views.V2Book.as_view()),
]
