未引发 IntegrityError 外键违规

如何解决未引发 IntegrityError 外键违规

使用下面的代码和以下序列，我怀疑存在外键违规的 IntegrityError。不幸的是，错误没有出现。

• 创建Customer(id=1)
• 创建Booking(cid=1)
• 删除Customer(id=1)

#main.py
from typing import List
from fastapi.params import Depends
from schemas import Customer,ShowCustomer,Booking,ShowBooking
from fastapi import FastAPI,HTTPException
from database import get_db,engine,Base
from sqlalchemy.orm import Session
import models

    
models.Base.Metadata.create_all(engine)
app = FastAPI()
   
@app.post("/customer")
async def customer(req: Customer,db: Session=Depends(get_db)):
    new_customer=models.Customer(name=req.name,type=req.type)
    db.add(new_customer)
    db.commit()
    db.refresh(new_customer)
    return new_customer
    
@app.get("/customer",response_model=List[ShowCustomer])
async def create(db: Session=Depends(get_db)):
    customers=db.query(models.Customer).all()
    return customers
   
@app.delete('/customer/{id}')
def destory(id,db: Session=Depends(get_db)):
    customer=db.query(models.Customer).filter(models.Customer.id == id)
    if not customer.first():
        raise HTTPException(status_code=404,detail=f'Blog with the id {id} is not available '
        )
    customer.delete(synchronize_session=False)
    db.commit()
    return 'done'
    
    
@app.post("/booking")
async def read_root(req: Booking,db: Session=Depends(get_db)):
    new_booking=models.Booking(name=req.name,type=req.type,cid=1)
    db.add(new_booking)
    db.commit()
    db.refresh(new_booking)
    return new_booking
    
@app.get("/booking",response_model=List[ShowBooking])
async def read_root(db: Session=Depends(get_db)):
    bookings=db.query(models.Booking).all()
    return bookings

# schemas.py
from pydantic import BaseModel
    

class Customer(BaseModel):
    name:str
    type:str

    
class ShowCustomer(Customer):
    id:int
    class Config():
        orm_mode = True
    

class Booking(BaseModel):
    name:str
    type:str
    

class ShowBooking(Booking):
    id:int
    cid:int
    class Config():
        orm_mode = True

#models.py
from sqlalchemy import Column,Integer,String,ForeignKey
from sqlalchemy.orm import relationship
from database import Base
    

class Customer(Base):
    __tablename__ = "customers"
        
    id = Column(Integer,primary_key=True,index=True)
    name = Column(String)
    type = Column(String)
    booking = relationship("Booking",back_populates="customer")
        

class Booking(Base):
    __tablename__ = "bookings"
        
    id = Column(Integer,index=True)
    cid = Column(Integer,ForeignKey("customers.id"),nullable=False)
    name = Column(String)
    type = Column(String)
    customer = relationship('Customer',back_populates="booking")

#database.py
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
    
   
sqlALCHEMY_DATABASE_URL = 'sqlite:///./cloud2.db'
engine = create_engine(sqlALCHEMY_DATABASE_URL,connect_args={"check_same_thread": False})
SessionLocal = sessionmaker(bind=engine,autocommit=False,autoflush=False)
Base = declarative_base()
    
def get_db():
    db=SessionLocal()
    try:
        yield db
    finally:
        db.close()