尽管 DB/model 中有数据，但 FastAPI 没有选择嵌套模式
FastAPI is not picking up a nested schema despite the data being there in the DB/model
我在尝试 return 将数据存储在两个模型之间的关系中时遇到错误。更多信息如下：
models.py（相关型号为Company和Address）
from datetime import datetime
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from sqlalchemy import Column, Integer, String, Date, Sequence, ForeignKey, DateTime
try:
from .functions import to_camelcase
except:
from functions import to_camelcase
Base = declarative_base()
class ToDictMixin(object):
def to_dict(self, camelcase=True):
if camelcase:
return {to_camelcase(column.key): getattr(self, attr) for attr, column in self.__mapper__.c.items()}
else:
return {column.key: getattr(self, attr) for attr, column in self.__mapper__.c.items()}
class TimestampMixin(object):
record_created = Column('record_created', DateTime, default=datetime.now())
class Company(Base, ToDictMixin, TimestampMixin):
__tablename__ = 'companies'
number = Column(Integer, primary_key=True)
name = Column(String)
incorporated = Column(Date)
address = relationship("Address", back_populates="occupier")
def __repr__(self):
return f"<Company(number='{self.number}', name='{self.name}', incorporated='{self.incorporated.isoformat}')>"
class Address(Base, ToDictMixin, TimestampMixin):
__tablename__ = 'addresses'
id = Column(Integer, primary_key=True)
address_line1 = Column(String)
address_line2 = Column(String)
address_line3 = Column(String)
po_box = Column(String)
post_town = Column(String)
county = Column(String)
postcode = Column(String)
country = Column(String)
occupier_id = Column(Integer, ForeignKey("companies.number"))
occupier = relationship("Company", back_populates="address")
schemas.py
import datetime
from pydantic import BaseModel, BaseConfig
from typing import List
from functions import to_camelcase
class APIBase(BaseModel):
class Config(BaseConfig):
orm_mode = True
alias_generator = to_camelcase
allow_population_by_field_name = True
class AddressBase(APIBase):
address_line1 : str
postcode: str
class AddressCreate(AddressBase):
pass
class Address(AddressBase):
address_line2 : str
address_line3 : str
po_box : str
post_town : str
county : str
postcode : str
country : str
class CompanyBase(APIBase):
number: int
name: str
class CompanyCreate(CompanyBase):
incorporated : datetime.date
class Company(CompanyBase):
incorporated : datetime.date
address: Address
main.py中的相关调用：
@app.get("/companies", response_model=List[schemas.Company])
def get_companies(
year: int = None, month: int = None, day: int = None, number: int = None,
name: str = None, db: Session = Depends(get_db)):
name = name.upper() if name else None
arguments = locals()
arguments.pop("db")
if not any(arguments.values()):
return None
myquery = db.query(models.Company)
datedict = {}
for key, value in arguments.items():
if key == "number" and datedict:
myquery = crud.get_company_by_date(db, **datedict)
if not value:
continue
if key == 'year' or key == 'month' or key == 'day':
datedict[key] = value
else:
myquery = crud.filter_query(myquery, **{key:value})
return myquery.all()
现在，据我从文档中得知，一切都已设置好。当我从 Company 模式中删除 address: Address 时，此调用将 return 正确的 company/companies 而没有地址数据。
我已通过测试
确认相关地址数据与公司模型相关联
>>> x = SESSION.query(Company).filter_by(number=12544331).one_or_none()
>>> x.address[0].address_line1
'4 VICTORIA COURT'
所以我知道数据在地址 table 中，关系设置正确，模型和架构在尝试将地址数据包含在结果中之前有效。但是，当我尝试访问 http://127.0.0.1:8000/companies?number=12544331 时，出现内部服务器错误和以下错误消息：
INFO: 127.0.0.1:50928 - "GET /companies?number=12544331 HTTP/1.1" 500 Internal Server Error
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\uvicorn\protocols\http\h11_impl.py", line 384, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\uvicorn\middleware\proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\fastapi\applications.py", line 149, in __call__
await super().__call__(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\applications.py", line 102, in __call__
await self.middleware_stack(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\middleware\errors.py", line 181, in __call__
raise exc from None
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\middleware\errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\exceptions.py", line 82, in __call__
raise exc from None
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\routing.py", line 550, in __call__
await route.handle(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\routing.py", line 227, in handle
await self.app(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\routing.py", line 41, in app
response = await func(request)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\fastapi\routing.py", line 204, in app
response_data = await serialize_response(
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\fastapi\routing.py", line 126, in serialize_response
raise ValidationError(errors, field.type_)
pydantic.error_wrappers.ValidationError: 8 validation errors for Company
response -> 0 -> address -> addressLine1
field required (type=value_error.missing)
response -> 0 -> address -> postcode
field required (type=value_error.missing)
response -> 0 -> address -> addressLine2
field required (type=value_error.missing)
response -> 0 -> address -> addressLine3
field required (type=value_error.missing)
response -> 0 -> address -> poBox
field required (type=value_error.missing)
response -> 0 -> address -> postTown
field required (type=value_error.missing)
response -> 0 -> address -> county
field required (type=value_error.missing)
response -> 0 -> address -> country
field required (type=value_error.missing)
似乎认为地址数据不存在。我认为这与 schemas.py 中的 orm_mode 有关，因为存在延迟加载，但我将 orm_mode 设置为 True 以避免这种情况（参见 https://fastapi.tiangolo.com/tutorial/sql-databases/#technical-details-about-orm-mode） .
拜托，我错过了什么？
原来是因为我在models.py中的关系定义。 SQLAlchemy 文档在此处对其进行了解释：https://docs.sqlalchemy.org/en/13/orm/basic_relationships.html#one-to-one
调整后的代码：
class Company(Base, ToDictMixin, TimestampMixin):
__tablename__ = 'companies'
number = Column(Integer, primary_key=True)
name = Column(String)
incorporated = Column(Date)
address = relationship("Address", uselist=False, back_populates="occupier")
def __repr__(self):
return f"<Company(number='{self.number}', name='{self.name}', incorporated='{self.incorporated.isoformat}')>"
注意uselist=False
的用法
我在尝试 return 将数据存储在两个模型之间的关系中时遇到错误。更多信息如下：
models.py（相关型号为Company和Address）
from datetime import datetime
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from sqlalchemy import Column, Integer, String, Date, Sequence, ForeignKey, DateTime
try:
from .functions import to_camelcase
except:
from functions import to_camelcase
Base = declarative_base()
class ToDictMixin(object):
def to_dict(self, camelcase=True):
if camelcase:
return {to_camelcase(column.key): getattr(self, attr) for attr, column in self.__mapper__.c.items()}
else:
return {column.key: getattr(self, attr) for attr, column in self.__mapper__.c.items()}
class TimestampMixin(object):
record_created = Column('record_created', DateTime, default=datetime.now())
class Company(Base, ToDictMixin, TimestampMixin):
__tablename__ = 'companies'
number = Column(Integer, primary_key=True)
name = Column(String)
incorporated = Column(Date)
address = relationship("Address", back_populates="occupier")
def __repr__(self):
return f"<Company(number='{self.number}', name='{self.name}', incorporated='{self.incorporated.isoformat}')>"
class Address(Base, ToDictMixin, TimestampMixin):
__tablename__ = 'addresses'
id = Column(Integer, primary_key=True)
address_line1 = Column(String)
address_line2 = Column(String)
address_line3 = Column(String)
po_box = Column(String)
post_town = Column(String)
county = Column(String)
postcode = Column(String)
country = Column(String)
occupier_id = Column(Integer, ForeignKey("companies.number"))
occupier = relationship("Company", back_populates="address")
schemas.py
import datetime
from pydantic import BaseModel, BaseConfig
from typing import List
from functions import to_camelcase
class APIBase(BaseModel):
class Config(BaseConfig):
orm_mode = True
alias_generator = to_camelcase
allow_population_by_field_name = True
class AddressBase(APIBase):
address_line1 : str
postcode: str
class AddressCreate(AddressBase):
pass
class Address(AddressBase):
address_line2 : str
address_line3 : str
po_box : str
post_town : str
county : str
postcode : str
country : str
class CompanyBase(APIBase):
number: int
name: str
class CompanyCreate(CompanyBase):
incorporated : datetime.date
class Company(CompanyBase):
incorporated : datetime.date
address: Address
main.py中的相关调用：
@app.get("/companies", response_model=List[schemas.Company])
def get_companies(
year: int = None, month: int = None, day: int = None, number: int = None,
name: str = None, db: Session = Depends(get_db)):
name = name.upper() if name else None
arguments = locals()
arguments.pop("db")
if not any(arguments.values()):
return None
myquery = db.query(models.Company)
datedict = {}
for key, value in arguments.items():
if key == "number" and datedict:
myquery = crud.get_company_by_date(db, **datedict)
if not value:
continue
if key == 'year' or key == 'month' or key == 'day':
datedict[key] = value
else:
myquery = crud.filter_query(myquery, **{key:value})
return myquery.all()
现在，据我从文档中得知，一切都已设置好。当我从 Company 模式中删除 address: Address 时，此调用将 return 正确的 company/companies 而没有地址数据。
我已通过测试
确认相关地址数据与公司模型相关联>>> x = SESSION.query(Company).filter_by(number=12544331).one_or_none()
>>> x.address[0].address_line1
'4 VICTORIA COURT'
所以我知道数据在地址 table 中，关系设置正确，模型和架构在尝试将地址数据包含在结果中之前有效。但是，当我尝试访问 http://127.0.0.1:8000/companies?number=12544331 时，出现内部服务器错误和以下错误消息：
INFO: 127.0.0.1:50928 - "GET /companies?number=12544331 HTTP/1.1" 500 Internal Server Error
ERROR: Exception in ASGI application
Traceback (most recent call last):
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\uvicorn\protocols\http\h11_impl.py", line 384, in run_asgi
result = await app(self.scope, self.receive, self.send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\uvicorn\middleware\proxy_headers.py", line 45, in __call__
return await self.app(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\fastapi\applications.py", line 149, in __call__
await super().__call__(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\applications.py", line 102, in __call__
await self.middleware_stack(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\middleware\errors.py", line 181, in __call__
raise exc from None
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\middleware\errors.py", line 159, in __call__
await self.app(scope, receive, _send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\exceptions.py", line 82, in __call__
raise exc from None
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\exceptions.py", line 71, in __call__
await self.app(scope, receive, sender)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\routing.py", line 550, in __call__
await route.handle(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\routing.py", line 227, in handle
await self.app(scope, receive, send)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\starlette\routing.py", line 41, in app
response = await func(request)
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\fastapi\routing.py", line 204, in app
response_data = await serialize_response(
File "c:\users\admin\google~1\python\new_co~1\env\lib\site-packages\fastapi\routing.py", line 126, in serialize_response
raise ValidationError(errors, field.type_)
pydantic.error_wrappers.ValidationError: 8 validation errors for Company
response -> 0 -> address -> addressLine1
field required (type=value_error.missing)
response -> 0 -> address -> postcode
field required (type=value_error.missing)
response -> 0 -> address -> addressLine2
field required (type=value_error.missing)
response -> 0 -> address -> addressLine3
field required (type=value_error.missing)
response -> 0 -> address -> poBox
field required (type=value_error.missing)
response -> 0 -> address -> postTown
field required (type=value_error.missing)
response -> 0 -> address -> county
field required (type=value_error.missing)
response -> 0 -> address -> country
field required (type=value_error.missing)
似乎认为地址数据不存在。我认为这与 schemas.py 中的 orm_mode 有关，因为存在延迟加载，但我将 orm_mode 设置为 True 以避免这种情况（参见 https://fastapi.tiangolo.com/tutorial/sql-databases/#technical-details-about-orm-mode） .
拜托，我错过了什么？
原来是因为我在models.py中的关系定义。 SQLAlchemy 文档在此处对其进行了解释：https://docs.sqlalchemy.org/en/13/orm/basic_relationships.html#one-to-one
调整后的代码：
class Company(Base, ToDictMixin, TimestampMixin):
__tablename__ = 'companies'
number = Column(Integer, primary_key=True)
name = Column(String)
incorporated = Column(Date)
address = relationship("Address", uselist=False, back_populates="occupier")
def __repr__(self):
return f"<Company(number='{self.number}', name='{self.name}', incorporated='{self.incorporated.isoformat}')>"
注意uselist=False