Firebase 查询数据

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

如果我像这样存储数据，并且我想获取节点id等于0。我怎样才能做到这一点？

上面是孩子issue，它是root.

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) {

    }
});