如何通过ID获取Firebase数据库类别数据并在单独的recyclerview中显示该数据？

Question

我是Firebase数据库中的新手，并且在单击sermoncategory recycerview时，我试图在android中将这样的数据检索到两个recyclerviews中，显示该数据的所有讲道，有人可以帮助我吗？与Android代码也谢谢！

"sermons"
        |_ _"0"
              |_ "sermonurl": "https://..."
              |_ "sermontitle": "Title"
              |_ "sermoncategory": "2"

        |_ _"1"
              |_ "sermonurl": "https://..."
              |_ "sermontitle": "Title"
              |_ "sermoncategory": "3"

    "sermoncategory"
           |
           |_ "2" 
               |_"categorytitle": "Covenant of Blessing"
               |_"categoryimageurl": "https://..."
               |_"categorydesciption":"bla bla bla"

           |_ "3"
               |_"categorytitle": "Healing"
               |_"categoryimageurl": "https://..."
               |_"categorydesciption":"bla bla bla"

Answer 1

如果您想使用sermoncategory为2的讲道，则可以使用orderByChild()这样的查询：

DatabaseReference ref = FirebaseDatabase.getInstance().getReference().child("sermons");

ref.orderByChild("sermoncategory").equalTo(2).addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
           // this dataSnapshot will have all the sermons with sermocategory as 2
        }

        @Override
        public void onCancelled(FirebaseError firebaseError) {
            Log.e("MainActivity", "onCancelled", firebaseError.toException());
        }
    });