掌握Django查询集排序：确保数据按预期顺序展示

# models.py

from django.db import models

class Task(models.Model):
    title = models.CharField(max_length=200)
    description = models.TextField(blank=True, null=True)
    created_at = models.DateTimeField(auto_now_add=True)
    updated_at = models.DateTimeField(auto_now=True)
    finished = models.BooleanField(default=False)
    # author = models.ForeignKey(User, on_delete=models.CASCADE) # 假设有User模型

    class Meta:
        # 默认按照id降序排列，即最新创建的在前
        # 如果模型有created_at字段，使用 ['-created_at'] 更符合“最新到最旧”的语义
        ordering = ['-id'] 
        # 或者 ordering = ['-created_at']
        # 也可以按多个字段排序：ordering = ['finished', '-updated_at']

    def __str__(self):
        return self.title

# views.py

from django.shortcuts import render, redirect
from .models import Task
from .forms import TaskForm # 假设您有一个TaskForm

def create_task(request):
    # 使用order_by()方法明确指定排序规则
    # 按照id降序排列，确保最新创建的任务在前
    tasks = Task.objects.all().order_by('-id') 
    # 如果Task模型有created_at字段，可以这样排序：
    # tasks = Task.objects.all().order_by('-created_at')
    # 如果想按更新时间排序：
    # tasks = Task.objects.all().order_by('-updated_at')

    if request.method == 'POST':
        task_id_update = request.POST.get('task_id_update')
        task_id_delete = request.POST.get('task_id_delete')

        if task_id_update:
            task = Task.objects.filter(id=task_id_update).first()
            if task: # 确保任务存在
                task.finished = True
                task.save()
            return redirect('/create_task') # 重定向以刷新列表
        elif task_id_delete:
            task = Task.objects.filter(id=task_id_delete).first()
            if task: # 确保任务存在
                task.delete()
            return redirect('/create_task') # 重定向以刷新列表
        else:
            form = TaskForm(request.POST)
            if form.is_valid():
                task = form.save(commit=False)
                # task.author = request.user # 如果有作者字段
                task.save()
                return redirect('/create_task')

    form = TaskForm()
    return render(request, 'main/create_task.html', {'form': form, 'tasks': tasks})