from sqlalchemy import Column, Integer, String, DateTime, Date, ForeignKey
from sqlalchemy.orm import relationship
from database import Base


class ClsMgmt(Base):
    """
    班级管理表模型
    对应 MySQL 中的 cls_mgmt 表
    """
    __tablename__ = "cls_mgmt"  # 表名

    # 字段定义
    id = Column(String(15), primary_key=True, nullable=False)          # 班级编号,主键，非空
    cls_start_date= Column(Date, nullable=False)                       #开课时间
    head_tea_id =Column(String(15), ForeignKey("tea_info.id"),nullable=False)                     # 班主任id
    lecturer_id=Column(String(15), ForeignKey("tea_info.id"),nullable=False)                      # 主讲老师id
    is_deleted=Column(Integer,nullable=False, default=0)

    stu = relationship("StuInfo",back_populates="cls")

    head_teacher = relationship("Teacher",
                                foreign_keys=[head_tea_id],
                                back_populates="head_classes")

    lecturer = relationship("Teacher",
                            foreign_keys=[lecturer_id],
                            back_populates="lecturer_classes")