我如何编写我的模型代码以根据我的数据库获取

How do I write up my models' code to fetch according to my database

FirebaseDatabase1 modellogcatRefview

不得不改变: val model = snapshot.getValue(BestDealModel::class.java) tempList.add(型号!!) 到 val model = itemSnapshot.getValue(BestDealModel::class.java) tempList.add(型号!!)