第六章：Model —— 行政档案制度从这里开始

from django.conf import settings
from django.db import models

class Permit(models.Model):
    class Status(models.TextChoices):
        PENDING = "pending", "待审批"
        APPROVED = "approved", "已批准"
        REJECTED = "rejected", "已驳回"

    title = models.CharField("事项标题", max_length=120)
    department = models.CharField("所属部门", max_length=50)
    description = models.TextField("申请说明", blank=True)
    status = models.CharField(
        "状态",
        max_length=20,
        choices=Status.choices,
        default=Status.PENDING,
    )
    created_by = models.ForeignKey(
        settings.AUTH_USER_MODEL,
        on_delete=models.CASCADE,
        related_name="permits",
        verbose_name="申请人",
    )
    created_at = models.DateTimeField("创建时间", auto_now_add=True)

    class Meta:
        ordering = ["-created_at"]
        verbose_name = "许可证申请"
        verbose_name_plural = "许可证申请"

    def __str__(self):
        return f"{self.title} ({self.get_status_display()})"

User（工作人员 / 市民）
  1
  │
  └─── N Permit（许可证申请）