订单高并发超卖解决方案（PHP）

fetch_assoc();
  if($row['number']>0){//高并发下会导致超卖
      if($row['number']<$number){
        return insertLog('库存不够',3,$username);
      }
      $order_sn=build_order_no();
      //库存减少
      $sql="update ih_store set number=number-{$number} where sku_id='$sku_id' and (number-{$number})>=0";
      $store_rs=mysqli_query($conn,$sql);
      if($store_rs){
          //生成订单
          insertOrder($order_sn,$user_id,$goods_id,$sku_id,$price,$username,$number);
          insertLog('库存减少成功',1,$username);
      }else{
          insertLog('库存减少失败',2,$username);
      }
  }else{
      insertLog('库存不够',3,$username);
  }
?>