from django.shortcuts import render
from django.http import HttpResponse
from django.views import View
from django.db import transaction   # 導(dǎo)入事務(wù)

class MyView(View):
 
    @transaction.atomic
    # transaction.atomic裝飾器可以保證該函數(shù)中所有的數(shù)據(jù)庫操作都在一個事務(wù)中。
    def post(self, request):
 
        # 數(shù)據(jù)庫操作1。。。
        # 數(shù)據(jù)庫操作2。。。
        
        return HttpResponse('ok')

class MyView2(View):
    @transaction.atomic
    def post(self, request):
 
        # 設(shè)置事務(wù)保存點
        s1 = transaction.savepoint()   # 可以設(shè)置多個保存點
 
        # 數(shù)據(jù)庫操作。。。
 
        # 事務(wù)回滾 (如果發(fā)生異常,就回滾事務(wù))
        transaction.savepoint_rollback(s1)  # 可以回滾到指定的保存點
 
        # 提交事務(wù) (如果沒有異常,就提交事務(wù))
        transaction.savepoint_commit(s1)
 
        # 返回應(yīng)答
        return HttpResponse('ok')

def func(request):
    with transaction.atomic():
        sid = transaction.savepoint()
        try:
            serializer.is_valid(raise_exception=True)
            comment = serializer.save()
            handle_obj_files(comment, request)
            visitor_order.epilogue.add(comment)
            visitor_order.status = 'complete'
            visitor_order.save()
        except Exception as e:
            transaction.savepoint_rollback(sid)
            return api_bad_request(str(e))
        else:
            transaction.savepoint_commit(sid)
        data = VisitorOrderRetrieveSerializer(visitor_order).data
        return api_success(data=data)