#导入需要用的工具
from sqlalchemy import Column, Integer, String, DateTime
from sqlalchemy.orm import relationship

from database import Base
from model.teacher_model import teacher_class

#班级表
class Classes(Base):
    __tablename__ = "classes"
    cid = Column(Integer, primary_key=True, autoincrement=True)
    class_name = Column(String(10), nullable=False)
    start_time = Column(DateTime,nullable=False)
    head_teacher = Column(String(10),nullable=False)
    teacher = Column(String(15),nullable=False)
    is_del = Column(Integer, default=1)  # 与现有查询/删除接口一致：1有效，0删除
#老师表和班级表多对多
    teachers = relationship("Teacher", secondary=teacher_class, back_populates="classes")
# #班级表和学生表一对多
    students = relationship("Student", back_populates="classes")