Python 如何在创建另一个模型后更新相关模型?
创建Python 如何在创建另一个模型后更新相关模型?,python,django,django-rest-framework,sql-update,Python,Django,Django Rest Framework,Sql Update,创建交易时,我需要自动更新我的帐户的金额 我有事务模型的model.py: class Transaction(models.Model): user = models.ForeignKey(User, default=None) account = models.ForeignKey(Account, default=None) ... class TransactionSerializer(serializers.ModelSerializer): clas
交易时,我需要自动更新我的帐户的金额
我有事务
模型的model.py
:
class Transaction(models.Model):
user = models.ForeignKey(User, default=None)
account = models.ForeignKey(Account, default=None)
...
class TransactionSerializer(serializers.ModelSerializer):
class Meta:
model = Transaction
fields = ('id', 'user', 'account_id', 'category_id', 'name', 'amount', 'description', 'created_at')
def create(self, validated_data):
return Transaction.objects.create(**validated_data)
class TransactionList(APIView):
def get(self, request):
user_id = request.user.pk
transactions = Transaction.objects.filter(user_id=user_id).order_by('-created_at')
serializer = TransactionSerializer(transactions, many=True)
return Response(serializer.data)
def post(self, request):
account_id = request.data['account_id']
category_id = request.data['category_id']
serializer = TransactionSerializer(data=request.data)
if serializer.is_valid():
serializer.save(user=request.user, account_id=account_id, category_id=category_id)
self.update_account(request)
return Response(serializer.data, status=HTTP_201_CREATED)
return Response(serializer.errors, status=HTTP_400_BAD_REQUEST)
def update_account(self, request):
account_id = request.data['account_id']
category_id = request.data['category_id']
account = Account.objects.get(pk=account_id)
category = Category.objects.get(pk=category_id)
if category.type == 'expense':
account.amount = (account.amount - int(self.request['amount']))
else:
account.amount = (account.amount + int(self.request['amount']))
# Then what?
其序列化程序.py
:
class Transaction(models.Model):
user = models.ForeignKey(User, default=None)
account = models.ForeignKey(Account, default=None)
...
class TransactionSerializer(serializers.ModelSerializer):
class Meta:
model = Transaction
fields = ('id', 'user', 'account_id', 'category_id', 'name', 'amount', 'description', 'created_at')
def create(self, validated_data):
return Transaction.objects.create(**validated_data)
class TransactionList(APIView):
def get(self, request):
user_id = request.user.pk
transactions = Transaction.objects.filter(user_id=user_id).order_by('-created_at')
serializer = TransactionSerializer(transactions, many=True)
return Response(serializer.data)
def post(self, request):
account_id = request.data['account_id']
category_id = request.data['category_id']
serializer = TransactionSerializer(data=request.data)
if serializer.is_valid():
serializer.save(user=request.user, account_id=account_id, category_id=category_id)
self.update_account(request)
return Response(serializer.data, status=HTTP_201_CREATED)
return Response(serializer.errors, status=HTTP_400_BAD_REQUEST)
def update_account(self, request):
account_id = request.data['account_id']
category_id = request.data['category_id']
account = Account.objects.get(pk=account_id)
category = Category.objects.get(pk=category_id)
if category.type == 'expense':
account.amount = (account.amount - int(self.request['amount']))
else:
account.amount = (account.amount + int(self.request['amount']))
# Then what?
及其视图.py
:
class Transaction(models.Model):
user = models.ForeignKey(User, default=None)
account = models.ForeignKey(Account, default=None)
...
class TransactionSerializer(serializers.ModelSerializer):
class Meta:
model = Transaction
fields = ('id', 'user', 'account_id', 'category_id', 'name', 'amount', 'description', 'created_at')
def create(self, validated_data):
return Transaction.objects.create(**validated_data)
class TransactionList(APIView):
def get(self, request):
user_id = request.user.pk
transactions = Transaction.objects.filter(user_id=user_id).order_by('-created_at')
serializer = TransactionSerializer(transactions, many=True)
return Response(serializer.data)
def post(self, request):
account_id = request.data['account_id']
category_id = request.data['category_id']
serializer = TransactionSerializer(data=request.data)
if serializer.is_valid():
serializer.save(user=request.user, account_id=account_id, category_id=category_id)
self.update_account(request)
return Response(serializer.data, status=HTTP_201_CREATED)
return Response(serializer.errors, status=HTTP_400_BAD_REQUEST)
def update_account(self, request):
account_id = request.data['account_id']
category_id = request.data['category_id']
account = Account.objects.get(pk=account_id)
category = Category.objects.get(pk=category_id)
if category.type == 'expense':
account.amount = (account.amount - int(self.request['amount']))
else:
account.amount = (account.amount + int(self.request['amount']))
# Then what?
我想创建一个自定义方法,如果序列化程序
有效,则该方法将在条件内执行,该方法将根据其id获取帐户和类别。到目前为止,我可以显示它们的当前值,例如金额
和名称
,但在此之后,我不知道该怎么办。我想我需要使用我的AccountSerializer
,但我不确定。最简单的方法是覆盖事务的save
方法
class Transaction(models.Model):
user = models.ForeignKey(User, default=None)
account = models.ForeignKey(Account, default=None)
...
def save(self, force_insert=False, force_update=False, using=None, update_fields=None):
super(Transaction, self).save()
# Update self.account
有关详细信息,请参阅。是否尝试了account.save()?