android – Firebase查询数据

{
  "random_key 1" : {
    "id": 0,"text": "This is text"
  },"random_key 2" : {
    "id": 1,"text": "This is text"
  }
}

如果我像这样存储我的数据,并且我想获得id等于0的节点.我该怎么做？

以上是问题的孩子,这是root的孩子.

解决方法

在您的情况下,您必须设置如下查询：

DatabaseReference reference = FirebaseDatabase.getInstance().getReference();

    Query query = reference.child("issue").orderByChild("id").equalTo(0);
    query.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            if (dataSnapshot.exists()) {
                // dataSnapshot is the "issue" node with all children with id 0
                for (DataSnapshot issue : dataSnapshot.getChildren()) {
                    // do something with the individual "issues"
                }
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });