Hello I am new in firebase and I need help with display subchildren of firebase which contain the same userID as signed user
here is users and edu1 full show of user
I need display just subchildren of signed user
and here is my code
private FirebaseAuth fAuth;
private DatabaseReference fNotesDatabase;
ArrayAdapter adapter;
ListView listView;
ArrayList<String> arraylist = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_education);
fAuth = FirebaseAuth.getInstance();
listView = findViewById(R.id.listview);
fNotesDatabase = FirebaseDatabase.getInstance().getReference().child("Notes").child("education");
fNotesDatabase.addListenerForSingleValueEvent(new ValueEventListener(){
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot datas: dataSnapshot.getChildren()){
String values = datas.getKey();
arraylist.add(values);
adapter = new ArrayAdapter(Education.this, android.R.layout.simple_list_item_single_choice, arraylist);
listView.setAdapter(adapter);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
Can you try this code and see if it is working with you :
FirebaseAuth mAuth = FirebaseAuth.getInstance();
// get the current user-id to read data easly
String currentUserId = mAuth.getCurrentUser().getUid();
DatabaseReference userRef = FirebaseDatabase.getInstance()
.getReference().child("notes").child("education");
// get data to them
userRef.child(currentUserId).addValueEventListener(
new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.exists()){
for(DataSnapshot datas: dataSnapshot.getChildren()){
String values = datas.getKey();
arraylist.add(values);
adapter = new ArrayAdapter(Education.this,
android.R.layout.simple_list_item_single_choice,
arraylist);
listView.setAdapter(adapter);
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
You seem to have a data structure like /Education/Notes/$uid. So to just read the notes of the currently signed in user, do:
fNotesDatabase = FirebaseDatabase.getInstance().getReference().child("Notes").child("education");
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
fNotesDatabase.child(uid).addListenerForSingleValueEvent(new ValueEventListener(){
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
...
Try the following:
FirebaseUser currentFirebaseUser = FirebaseAuth.getInstance().getCurrentUser();
String userId = currentFirebaseUser.getUid();
fNotesDatabase = FirebaseDatabase.getInstance().getReference().child("Notes").child("education");
fNotesDatabase.addListenerForSingleValueEvent(new ValueEventListener(){
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot datas: dataSnapshot.getChildren()){
String values = datas.getKey();
db = FirebaseDatabase.getInstance().getReference().child(values).orderByKey().equalTo(userId);
db.addListenerForSingleValueEvent(new ValueEventListener(){
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
//get data
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
Here you add reference to education then retrieve the direct children under education then using orderByKey() you can check if there is a key equal to the current logged in user and retrieve the data.
Related
Above is my firebase database I am trying to pull from.
As you can see I have a "table" called "Make". I have succesfully been able to pull this data into a Listview within my app. The code for this is below.
I now need to pull all the data from "VW_Data" table. This table has over 1000 childen named as "0" up to "1000" with the same headings in each such as "Bearing", "Altitude" etc but with different values. I would like to be able to pull "Bearing" value only from ALL 1000 children of "VW_Data" and display in a list.
However i have attempted only to try pull "VW_Data/0/Bearing" multiple ways which have not worked.
Here is my updated code for this class:
public class Graphview extends Activity
{
//Holds the values gathered from firebase
final ArrayList<String> graphlist = new ArrayList<>();
ArrayAdapter<String> arrayAdapter;
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
//Sets the layout according to the XML file
setContentView(R.layout.activity_graphview);
//XML variable
final ListView listViewG = findViewById(R.id.listviewG);
DatabaseReference database = FirebaseDatabase.getInstance().getReference().child("VW_Data");
database.addListenerForSingleValueEvent(new ValueEventListener()
{
#Override
public void onDataChange(DataSnapshot dataSnapshot)
{
for (DataSnapshot datas : dataSnapshot.getChildren())
{
String bearing = (String) datas.child("Bearing").getValue();
//Add the info retrieved from datasnapshot into the ArrayList
graphlist.add(bearing);
arrayAdapter = new ArrayAdapter<>(Graphview.this, R.layout.itemview, graphlist);
listViewG.setAdapter(arrayAdapter);
//Will refresh app when the data changes in the database
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}//End onCreate()
Try this :
DatabaseReference database = FirebaseDatabase.getInstance().getReference().child("VW_Data");
ref.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
Iterable<DataSnapshot> verticalSnapshotItr = dataSnapshot.getChildren();
if (verticalSnapshotItr != null) {
for (DataSnapshot verticalItemSnapshot : verticalSnapshotItr) {
String altitude = (String) verticalItemSnapshot.child("Altitude").getValue();
// Parse rest keys here
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
Try this:
DatabaseReference db = FirebaseDatabase.getInstance()
.getReference()
.child("VW_Data");
db.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot datas : dataSnapshot.getChildren()) {
String bearing = datas.child("Bearing").getValue().toString();
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
snapshot is at VW_Data then use the for loop, you will be able to iterate inside "0" and retrieve the value bearing
I was trying to retrieve the data from user and time. But I can't access the data, it's not really accessing the database.
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_balance);
mFirebaseDatabase=FirebaseDatabase.getInstance();
cashRef=mFirebaseDatabase.getReference().child("ASSETS").child("cash_at_bank");
TextView view=(TextView)findViewById(R.id.view);
view.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
cashRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
int time=dataSnapshot.getValue(int.class);
int values =dataSnapshot.getValue(int.class);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
});
To get the time, please use the following code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference cashAtBankRef = rootRef.child("ASSETS").child("Cash at bank");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
Long time = ds.child("time").child("time").getValue(Long.class);
Log.d("TAG", time + "");
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
cashAtBankRef.addListenerForSingleValueEvent(eventListener);
The output will be:
150555043995
//and so on
I have data in database:
database in firebase
I want read all child (Belgia, Czechy, Polska...) and display it in Text Field, but AFTER click the button (I don't change data in database).
The button have assigned below function:
public void f_btn_zaczytaj_dane(View view) {
myRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String value = dataSnapshot.getValue(String.class);
TextView txt_opis_panstwa = (TextView) findViewById(R.id.txt_opis_panstwa);
txt_opis_panstwa.setText(value);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
Befrore i write in code:
FirebaseDatabase database;
DatabaseReference myRef;
database = FirebaseDatabase.getInstance();
myRef = database.getReference("kraj");
Unfortunately, when I press the button nothing happens.
I will be grateful for the help
Regards, Marcin
You have to iterate through your children
public void f_btn_zaczytaj_dane(View view) {
myRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
TextView txt_opis_panstwa = (TextView) findViewById(R.id.txt_opis_panstwa);
for (DataSnapshot country : dataSnapshot.getChildren()) {
txt_opis_panstwa.append(country.getKey());
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
Please use this code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference krajRef = rootRef.child("flagiistolice").child("kraj");
public void f_btn_zaczytaj_dane(View view) {
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
TextView txt_opis_panstwa = (TextView) findViewById(R.id.txt_opis_panstwa);
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String country = ds.getkey();
txt_opis_panstwa.append(country);
Log.d("TAG", country);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
krajRef.addListenerForSingleValueEvent(eventListener);
}
I want to read back the data in Firebase which is medical = "Diabetes" which key in by the user.If this user has the medical history of diabetes will display something not allow the user to buy. Anyone can teach me how to write this condition in the android studio?
Firebase data structure
public class Pain_and_Fever extends AppCompatActivity implements View.OnClickListener{
private Button btnSubmit, btnCancel;
private String userID;
Query query;
//add Firebase Database stuff
private FirebaseDatabase mFirebaseDatabase;
private FirebaseAuth mAuth;
private FirebaseAuth.AuthStateListener mAuthListener;
private DatabaseReference myRef;
#Override
protected void onCreate(#Nullable final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_pain_and__fever);
btnSubmit = (Button) findViewById(R.id.bttnsubmit);
btnCancel = (Button) findViewById(R.id.bttncancel);
//declare the database reference object. This is what we use to access the database.
//NOTE: Unless you are signed in, this will not be useable.
mAuth = FirebaseAuth.getInstance();
mFirebaseDatabase = FirebaseDatabase.getInstance();
final FirebaseUser user = mAuth.getCurrentUser();
userID = user.getUid();
myRef = mFirebaseDatabase.getReference();
btnSubmit.setOnClickListener(this);
btnCancel.setOnClickListener(this);
query = myRef.orderByChild("medical").equalTo("Diabetes");
}
private void submit(){
query.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.exists()){
for (DataSnapshot issue : dataSnapshot.getChildren()){
UserInformation uInfo = issue.getValue(UserInformation.class);
if (uInfo.getMedical().equals("Diabetes")){
startActivity(new Intent(getApplicationContext(),Medicine.class));
}else{
myRef.child("Medicines").child("Pain and Fever").child(userID).setValue("Acetaminophen");
startActivity(new Intent(getApplicationContext(),Medicine.class));
}
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
#Override
public void onClick(View view) {
if (view == btnSubmit){
submit();
}
if (view == btnCancel){
startActivity(new Intent(this,Medicine.class));
}
}
}
Try this way, this works for me
Query chatRoomsQuery = mFirebaseDatabase.orderByChild("medical").equalTo("your value");
chatRoomsQuery.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
// dataSnapshot is the "issue" node with all children with id 0
search_list=new ArrayList<SearchModel>();
for (DataSnapshot issue : dataSnapshot.getChildren()) {
// do something with the individual "issues"
UserRegisterModel mModel = issue.getValue(UserRegisterModel.class);
if(mModel.getArea().equals(sel_area))
hidepDialog();
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
This is my randomly retrieving data codes:
mDataSelect.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
List<String> lst = new ArrayList<String>();
for (DataSnapshot ds : dataSnapshot.getChildren()) {
Collections.shuffle(lst);
lst.add(String.valueOf(ds.getKey()));
randomGenerator = new Random();
int index = randomGenerator.nextInt(lst.size());
String item = lst.get(index);
idofcaps.setText(item);
final DatabaseReference capsSelect = mDataSelect.child(item);
capsSelect.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dss) {
String post_Image = (String) dss.child("Image").getValue();
Picasso.with(StartCapsActivity.this).load(post_Image).into(caps);
String post_name = (String) dss.child("Translation").getValue();
translation.setText(post_name);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
});
I have a next button in my screen which has the same code for retrieve another image from database. However, I don't want to retrieve same image again. How can I prevent this redundancy?
Create an arraylist then add the retrieved key. Then remove possible duplicate keys. How do I remove repeated elements from ArrayList?