Django4全栈进阶之路21 项目实战（在线报修）：创建App应用和Model模型

1. 创建应用App

   • python manage.py startapp RepairApp

2. 创建模型

　　　　在models.py文件中定义一个Repair模型来表示报修单，其中包含以下字段：

• • repair_id: 报修单号
  • repair_time: 报修时间
  • repair_person: 报修人
  • problem_description: 问题描述
  • service_person: 接单人
  • response_time: 首次回应时间
  • progress: 处理进度

  • from django.db import models
    
    # Create your models here.
    from django.db import models
    import datetime
    
    from django.db.models.signals import pre_save
    from django.dispatch import receiver
    
    # 报修单状态choices
    STATUS_CHOICES = (
        ('1', '待受理'),
        ('2', '处理中'),
        ('3', '已完成'),
        ('4', '已撤销'),
    )
    
    class Repair(models.Model):
        repair_id = models.CharField(max_length=20, unique=True, verbose_name="报修单号")
        repair_time = models.DateTimeField(auto_now_add=True, verbose_name="报修时间")
        emp_id = models.CharField(max_length=20)
        repair_person = models.CharField(max_length=20, verbose_name="报修人")
        repair_description = models.TextField(verbose_name="问题描述")
        receiver = models.CharField(max_length=20, verbose_name="接单人", null=True, blank=True)
        first_response_time = models.DateTimeField(null=True, blank=True, verbose_name="首次回应时间")
        process_status = models.CharField(max_length=1, choices=STATUS_CHOICES, default='1', verbose_name="处理进度")
        created_time = models.DateTimeField(auto_now_add=True, verbose_name="创建时间")
        update_time = models.DateTimeField(auto_now=True, verbose_name="最后修改时间")
    
        def __str__(self):
            return self.repair_id
    
        class Meta:
            verbose_name = "报修单"
            verbose_name_plural = "报修单"
            ordering = ['-repair_time']
    
    @receiver(pre_save, sender=Repair)
    def auto_generate_repair_id(sender, instance, **kwargs):
        if not instance.repair_id:
            # 生成年月
            year_month = datetime.datetime.now().strftime("%Y%m")
            # 查找当月最大的流水号
            last_repair = Repair.objects.filter(repair_id__startswith=year_month).order_by('-repair_id').first()
            if last_repair:
                # 如果存在，流水号为最大报修单号加1
                max_id = int(last_repair.repair_id[-4:])
                new_id = f"{year_month}{max_id + 1:04}"
            else:
                # 如果不存在，流水号从0001开始
                new_id = f"{year_month}0001"
            instance.repair_id = new_id