Relevant image
最终的FirebaseUser fUser = FirebaseAuth.getInstance()。getCurrentUser();
DatabaseReference ref = FirebaseDatabase.getInstance()。getReference(“ Students”);
final DatabaseReference refOne = FirebaseDatabase.getInstance().getReference("Users");
ref.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
userList.clear();
for (DataSnapshot ds:dataSnapshot.getChildren()){
ModelUser modelUser = ds.getValue(ModelUser.class);
{
userList.add(modelUser);
}
//adapter
adapterUsers = new AdapterUser(Parent_LoginActivity.this, userList);
//set adapter to recyclerview
recyclerView.setAdapter(adapterUsers);
}
}
最佳答案
您可能需要先检索数据并将其插入列表,然后比较并检索所需的数据。 Firebase方法对查询的作用不及SQL。