When Sqlalchemy deletes records with foreign key constraints, the foreign key constraints do not work. What is the solution?

One 、 Environmental Science ：pyqt5+python 3.7+SQLAlchemy 1.4.36+mysql 8.0

Two 、 The relevant table structure is as follows ：

class maintenanceZone(Base):    __tablename__ = "maintenanceZone"  #  Regional information     __table_args__ = {        "mysql_engine": "InnoDB",    }    id = sa.Column(sa.Integer(), primary_key=True, autoincrement=True)    cityName = sa.Column(sa.String(100), nullable=False )    countyName = sa.Column(sa.String(100), nullable=False)class maintainerInfo(Base):    __tablename__ = "maintainerInfo"  # Personnel information     __table_args__ = {        "mysql_engine": "InnoDB",    }    id = sa.Column(sa.Integer(), primary_key=True, autoincrement=True)    userName = sa.Column(sa.String(100), unique=True, nullable=False, comment=" Name of person ")    userPhone = sa.Column(sa.String(20), unique=True, comment=" Contact number of personnel ")    zoneID = sa.Column(sa.Integer(),                       sa.ForeignKey("maintenanceZone.id", ondelete="RESTRICT",onupdate="CASCADE"), comment=" Area ID")    zoneinfo = relationship("maintenanceZone", backref=backref('maintainerInfo',order_by=id))

3、 ... and 、 The relevant code is as follows ：

zoneOne = session.query(maintenanceZone).filter(maintenanceZone.cityName == old_city,maintenanceZone.countyName == old_country).one()session.delete(zoneOne)session.commit()

Four 、 database engine The code is as follows ：

dburl = "mysql+pymysql://{}:{}@{}:{}/{}?charset=utf8".format(dbIni["user"], dbIni["password"],dbIni["host"], dbIni["port"], dbIni["db"])engine = create_engine(            url=dburl,            max_overflow=0,             pool_size=5,            pool_timeout=20,            pool_recycle=-1,        )

5、 ... and 、 Questions as follows ：

1、 stay mysql8.0 in , adopt sql Language deletion maintenanceZone When recorded in the table , Will trigger foreign key constraints , Prompt cannot be deleted ;

2、 stay python Passed in code SQLAlchemy Delete maintenanceZone When the same record in the table , There's no hint , Delete directly ！

 

SQLAlchemy Delete maintenanceZone When the table records , Foreign key constraint is not effective ？？？？？