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


class Student(Base):
    __tablename__ = "students"
    id = Column(String(20), primary_key=True, comment="学号")# 主键：学号

    name = Column(String(50), nullable=False, comment="学生姓名")
    gender = Column(String(10), nullable=False, comment="性别：男 / 女")
    age = Column(Integer, comment="年龄")
    hometown = Column(String(100), comment="籍贯")
    graduate_school = Column(String(100), comment="毕业学校")
    major = Column(String(50), comment="专业")
    education = Column(String(30), comment="专科/本科/硕士")
    enrollment_date = Column(Date, comment="入学时间")
    graduation_date = Column(Date, comment="毕业时间")
    status = Column(String(20), default="在读", comment="状态：没有毕业/未就业/已就业")
    is_deleted = Column(Boolean, default=False, comment="逻辑删除标记")
    # 外键 班级编号
    class_name = Column(String(20), ForeignKey("classes.class_name"), comment="所属班级编号")

    # 关系映射   学生和就业 一对一，一个学生对应一条就业信息    学生和成绩一对多，一个学生对应多条成绩
    scores = relationship("Scores", back_populates="student")     # 一个学生多次考核成绩
    employment = relationship("Employments", back_populates="student", uselist=False)  # 一对一就业信息
    classes = relationship("Classes", back_populates="students")

    def __repr__(self):
        return f"<Student(no={self.id}, name={self.name}, class={self.class_name})>"