from django.db import transaction
@transaction.atomic
def viewfunc(request):
  # 這些代碼會在一個事務(wù)中執(zhí)行
  ...
from django.db import transaction
def viewfunc(request):
  # 這部分代碼不在事務(wù)中，會被Django自動提交
  ...
  with transaction.atomic():
    # 這部分代碼會在事務(wù)中執(zhí)行
    ...　 

from django.db import transaction
# 創(chuàng)建保存點(diǎn)
save_id = transaction.savepoint() 
# 回滾到保存點(diǎn)
transaction.savepoint_rollback(save_id)
# 提交從保存點(diǎn)到當(dāng)前狀態(tài)的所有數(shù)據(jù)庫事務(wù)操作
transaction.savepoint_commit(save_id)

def create(self, validated_data): """ 保存訂單 """ # 獲取當(dāng)前下單用戶 user = self.context['request'].user # 組織訂單編號 20170903153611+user.id # timezone.now() -> datetime order_id = timezone.now().strftime('%Y%m%d%H%M%S') + ('%09d' % user.id) address = validated_data['address'] pay_method = validated_data['pay_method'] # 生成訂單 with transaction.atomic(): # 創(chuàng)建一個保存點(diǎn) save_id = transaction.savepoint() try: # 創(chuàng)建訂單信息 order = OrderInfo.objects.create( order_id=order_id, user=user, address=address, total_count=0, total_amount=Decimal(0), freight=Decimal(10), pay_method=pay_method, status=OrderInfo.ORDER_STATUS_ENUM['UNSEND'] if pay_method == OrderInfo.PAY_METHODS_ENUM['CASH'] else OrderInfo.ORDER_STATUS_ENUM['UNPAID'] ) # 獲取購物車信息 redis_conn = get_redis_connection("cart") redis_cart = redis_conn.hgetall("cart_%s" % user.id) cart_selected = redis_conn.smembers('cart_selected_%s' % user.id) # 將bytes類型轉(zhuǎn)換為int類型 cart = {} for sku_id in cart_selected: cart[int(sku_id)] = int(redis_cart[sku_id]) # # 一次查詢出所有商品數(shù)據(jù) # skus = SKU.objects.filter(id__in=cart.keys()) # 處理訂單商品 sku_id_list = cart.keys() for sku_id in sku_id_list: while True: sku = SKU.objects.get(id=sku_id) sku_count = cart[sku.id] # 判斷庫存 origin_stock = sku.stock # 原始庫存 origin_sales = sku.sales # 原始銷量 if sku_count > origin_stock: transaction.savepoint_rollback(save_id) raise serializers.ValidationError('商品庫存不足') # 用于演示并發(fā)下單 # import time # time.sleep(5) # 減少庫存 # sku.stock -= sku_count # sku.sales += sku_count # sku.save() new_stock = origin_stock - sku_count new_sales = origin_sales + sku_count # 根據(jù)原始庫存條件更新，返回更新的條目數(shù)，樂觀鎖 ret = SKU.objects.filter(id=sku.id, stock=origin_stock).update(stock=new_stock, sales=new_sales) if ret == 0: continue # 累計(jì)商品的SPU 銷量信息 sku.goods.sales += sku_count sku.goods.save() # 累計(jì)訂單基本信息的數(shù)據(jù) order.total_count += sku_count # 累計(jì)總金額 order.total_amount += (sku.price * sku_count) # 累計(jì)總額 # 保存訂單商品 OrderGoods.objects.create( order=order, sku=sku, count=sku_count, price=sku.price, ) # 更新成功 break # 更新訂單的金額數(shù)量信息 order.total_amount += order.freight order.save() except serializers.ValidationError: raise except Exception as e: logger.error(e) transaction.savepoint_rollback(save_id) raise # 提交事務(wù) transaction.savepoint_commit(save_id) # 更新redis中保存的購物車數(shù)據(jù) pl = redis_conn.pipeline() pl.hdel('cart_%s' % user.id, *cart_selected) pl.srem('cart_selected_%s' % user.id, *cart_selected) pl.execute() return order

OpenSSL> genrsa -out app_private_key.pem  2048 # 私鑰 OpenSSL> rsa -in app_private_key.pem -pubout -out app_public_key.pem # 導(dǎo)出公鑰 OpenSSL> exit

class PaymentView(APIView):
  """
  支付
  """
  permission_classes = (IsAuthenticated,)
  def get(self, request, order_id):
    """
    獲取支付鏈接
    """
    # 判斷訂單信息是否正確
    try:
      order = OrderInfo.objects.get(order_id=order_id, user=request.user,
                     pay_method=OrderInfo.PAY_METHODS_ENUM["ALIPAY"],
                     status=OrderInfo.ORDER_STATUS_ENUM["UNPAID"])
    except OrderInfo.DoesNotExist:
      return Response({'message': '訂單信息有誤'}, status=status.HTTP_400_BAD_REQUEST)
    # 構(gòu)造支付寶支付鏈接地址
    alipay = AliPay(
      appid=settings.ALIPAY_APPID,
      app_notify_url=None, # 默認(rèn)回調(diào)url
      app_private_key_path=os.path.join(os.path.dirname(os.path.abspath(__file__)), "keys/app_private_key.pem"),
      alipay_public_key_path=os.path.join(os.path.dirname(os.path.abspath(__file__)), "keys/alipay_public_key.pem"), # 支付寶的公鑰，驗(yàn)證支付寶回傳消息使用，不是你自己的公鑰,
      sign_type="RSA2", # RSA 或者 RSA2
      debug=settings.ALIPAY_DEBUG # 默認(rèn)False
    )
    order_string = alipay.api_alipay_trade_page_pay(
      out_trade_no=order_id,
      total_amount=str(order.total_amount),
      subject="美多商城%s" % order_id,
      return_url="http://www.meiduo.site:8080/pay_success.html", 
    )
    # 需要跳轉(zhuǎn)到https://openapi.alipay.com/gateway.do? + order_string
    # 拼接鏈接返回前端
    alipay_url = settings.ALIPAY_URL + "?" + order_string
    return Response({'alipay_url': alipay_url})