python 实用库收集

pydantic的orm_mode可以与sqlalchemy ORM联动

单一表的情况

from sqlalchemy import Column, String, Integer
from sqlalchemy.ext.declarative import declarative_base
from pydantic import BaseModel, constr


Base = declarative_base()




class ParentORM(Base):
    __tablename__ = 'parent'


    id = Column(Integer, primary_key=True, autoincrement=True, index=True)
    name = Column(String(30))
    age = Column(Integer)




class Parent(BaseModel):
    id: int
    name: constr(max_length=30)
    age: int


    class Config:
        orm_mode = True




if __name__ == '__main__':
    p_orm = ParentORM(id=1, name='John', age=30)
    p = Parent.from_orm(p_orm)
    print(p.name)

多个表关联

from typing import List
from sqlalchemy import Column, String, Integer, ForeignKey
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship
from pydantic import BaseModel, constr


Base = declarative_base()




class ParentORM(Base):
    __tablename__ = 'parent'


    id = Column(Integer, primary_key=True, autoincrement=True, index=True)
    name = Column(String(30))
    age = Column(Integer)


    children = relationship(
        "ChildORM", foreign_keys='ChildORM.parent_id', back_populates='parent'
    )




class ChildORM(Base):
    __tablename__ = 'child'


    id = Column(Integer, primary_key=True, autoincrement=True, index=True)
    name = Column(String(30))
    age = Column(Integer)
    interests = Column(String(30))


    parent_id = Column(Integer, ForeignKey('parent.id'))


    parent = relationship(
        'ParentORM', foreign_keys='ChildORM.parent_id', back_populates='children'
    )




# 注意这个类的定义顺序, 因为后面要用到这个类，所以需要放在前面
class Children(BaseModel):
    id: int
    name: constr(max_length=30)
    age: int
    interests: constr(max_length=30)


    class Config:
        orm_mode = True




class Parent(BaseModel):
    id: int
    name: constr(max_length=30)
    age: int


    # 这里定义的是一个列表，pydantic 会自动把关联的类放在这里
    children: List[Children] = []


    class Config:
        orm_mode = True




if __name__ == '__main__':
    p_orm = ParentORM(id=1, name='John', age=30)
    c_orm = ChildORM(id=1, name='kk', age=10, interests='football')
    c_orm_2 = ChildORM(id=2, name='link', age=4, interests='basketball')


    c_orm.parent = p_orm
    c_orm_2.parent = p_orm


    p = Parent.from_orm(p_orm)


    print(len(p.children))
    print(p.children[0].name)

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