Python SQLALCHEMY我如何创建此表？

为了结束，答案是将

fine

类移到

create\u all

语句之前，因为这是它创建必要表的部分

i、 e

---

欢迎来到SO。请尝试将

fine

类定义移到

Base.metadata.create_all（bind=engine）

前面，非常感谢！

from sqlalchemy import create_engine from sqlalchemy.ext.declarative import declarative_base from sqlalchemy.orm import sessionmaker from sqlalchemy import Column, Integer, String

SQLALCHEMY_DATABASE_URL = "mysql+pymysql://root:1234@localhost:3306/lunch"

engine= create_engine(
    SQLALCHEMY_DATABASE_URL )

SessionLocal= sessionmaker(autocommit=False, autoflush=False, bind= engine)


Base = declarative_base() db= SessionLocal()

Base.metadata.create_all(bind=engine)

class Meal(Base):
    __tablename__= 'meals'
    id= Column(Integer, primary_key=True, autoincrement=True)  
    sandwich = Column(String(20), nullable=False)
    fruit = Column(String(20), nullable=False)
    tablenumber= Column(Integer)
    def __repr__(self):
        return '[{}, {}, {},{}]'.format(self.id, self.sandwich, self.fruit, self.tablenumber)

meal = Meal(id=1, sandwich='Libanais', fruit='banane', tablenumber= 21) print('----->', meal) db.add(meal) db.commit()



sqlalchemy.exc.ProgrammingError: (pymysql.err.ProgrammingError) (1146, "Table 'lunch.meals' doesn't exist") [SQL: INSERT INTO meals (id, sandwich, fruit, tablenumber) VALUES (%(id)s, %(sandwich)s, %(fruit)s, %(tablenumber)s)] [parameters: {'id': 1, 'sandwich': 'Libanais', 'fruit': 'banane', 'tablenumber': 21}] (Background on this error at: http://sqlalche.me/e/13/f405)

from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from sqlalchemy import Column, Integer, String

SQLALCHEMY_DATABASE_URL = "mysql+pymysql://root:1234@localhost:3306/lunch"

engine = create_engine(SQLALCHEMY_DATABASE_URL )

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


Base = declarative_base()
db = SessionLocal()


class Meal(Base):
    __tablename__= 'meals'

    id = Column(Integer, primary_key=True, autoincrement=True)  
    sandwich = Column(String(20), nullable=False)
    fruit = Column(String(20), nullable=False)
    tablenumber = Column(Integer)

    def __repr__(self):
        return '[{}, {}, {},{}]'.format(self.id, self.sandwich,
                                        self.fruit, self.tablenumber)

Base.metadata.create_all(bind=engine)

meal = Meal(id=1, sandwich='Libanais', fruit='banane', tablenumber= 21) print('----->', meal)

db.add(meal)
db.commit()