Develop Reference

I want to retrieve two values from uniquely identified data in firebase

that's my database
{
"users" : {
"-MdgDcU3Zb-TiLlTwfwU" : {
"email" : "t1#email.com",
"fname" : "test",
"lname" : "1",
"password" : "t1",
"phoneno" : "304*******"
},
"-MdgNDN23XCTyB4DsF4W" : {
"email" : "t2#email.com",
"fname" : "test",
"lname" : "2",
"password" : "t2",
"phoneno" : "333*******"
}
}
}
that's the login activity's code
DatabaseReference reference= FirebaseDatabase.getInstance().getReference("users");
Query checkUser = reference.orderByChild("phoneno").equalTo(userphoneno);
checkUser.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot snapshot) {
if(snapshot.exists()){
//editTextphoneno.setError(null);
//editTextphoneno.setErrorEnabled(false);
String passwordFromDB =snapshot.child(userphoneno).child("password").getValue(String.class);
if(passwordFromDB.equals(userpassword)){
//editTextphoneno.setError(null);
//editTextphoneno.setErrorEnabled(false);
Intent i = new Intent(Login_page.this, Bottomnav.class);
startActivity(i);
finish();
}else{
editTextpassword.setError("Invalid Password");
editTextpassword.requestFocus();
}
}else{
editTextphoneno.setError("Invalid Phone Number");
editTextphoneno.requestFocus();
}
}
I want the user to login through his phone number and password but every time, after entering phone no and password I click on login, the app crashes. What I have understood is that may be the user's phone number and password is not being retrieved successfully.

When you are using the following query:
DatabaseReference reference= FirebaseDatabase.getInstance().getReference("users");
Query checkUser = reference.orderByChild("phoneno").equalTo(userphoneno);
It means that you are searching the "users" node, for all users who have the "phoneno" equal to "userphoneno". This also means that such a query may potentially return multiple results. Even if the query returns a single result, you'll need to loop through the DataSnapshot object using getChildren() method, as in the following lines of code:
checkUser.get().addOnCompleteListener(new OnCompleteListener<DataSnapshot>() {
#Override
public void onComplete(#NonNull Task<DataSnapshot> task) {
if (task.isSuccessful()) {
for (DataSnapshot ds : task.getResult().getChildren()) {
String passwordFromDB = ds.child("password").getValue(String.class);
Log.d("TAG", passwordFromDB);
//Add your logic
}
} else {
Log.d("TAG", task.getException().getMessage()); //Don't ignore potential errors!
}
}
});
Please see that inside onComplete, in order to get the password, there is no need for a .child(userphoneno) call, as the "password" is already a child of the DataSnapshot object.
More important, never store sensitive data as passwords in plain text. Malicious users might take advantage of that. Use Firebase Authentication for that and secure the database using Firestore Security Rules.

Unable to update value in Firebase database from Android app

With the following code, I have the "history node".
History Node
{
"History" : {
"-LJANnl9ofbXlxLGxTGg" : {
"destination" : "3 Paradise Row",
"driver" : "ReGqRl2IIUhmLIqdBqBIELHBsgE3",
"location" : "1 Union St",
"payment response" : "approved",
"rating" : 0,
"ridePrice" : 5.25,
"rider" : "l3PPyBQux7YJhGGTdexxwDBteLM2",
"riderPaid" : "true",
"status" : "accepted",
"timestamp" : 1533494377
}
}
With the following code, I am trying to update "status" value to update from "accepted" to "arrived_loc". When I run the code, I have a yellow highlight in firebase but keeps the value of status "accepted".
update status to "arrived_loc"
driverId = FirebaseAuth.getInstance().getCurrentUser().getUid();
final DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
Query query = rootRefchild("History").orderByChild("driver").equalTo(driverId);
query.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
DataSnapshot nodeDS = dataSnapshot.getChildren().iterator().next();
String key = nodeDS.getKey();
Log.e(TAG, "key = " + key);
String path = "/" + dataSnapshot.getKey() + "/" + key;
Log.e(TAG, "path = " + path);
HashMap<String, Object> update = new HashMap<>();
update.put("status", "arrived_loc");
rootRef.child(path).updateChildren(update);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
What am I doing wrong?
Edit #1
If I run this code:
DatabaseReference arrivedLoc = FirebaseDatabase.getInstance().getReference("History");
String historyId = arrivedLoc.push().getKey();
arrivedLoc.child(historyId).child("status").setValue("arrived at pickup");
I get an extra history node and no update:
"History" : {
"-LJAVN2iAWfRREdlBevb" : {
"destination" : "3 Union St",
"driver" : "ReGqRl2IIUhmLIqdBqBIELHBsgE3",
"location" : "123 Main Street",
"payment response" : "approved",
"rating" : 0,
"ridePrice" : 5.38,
"rider" : "l3PPyBQux7YJhGGTdexxwDBteLM2",
"riderPaid" : "true",
"status" : "accepted",
"timestamp" : 1533496391
},
"-LJAVaFd3Gzq3iIZGHeP" : {
"payment response" : "approved",
"riderPaid" : "true",
"status" : "accepted"
}
}
Edit #2 - image of database frozen
Edit #3
I can't seem to get it working for some reason so I renamed "status" to be "requestStatus" and created a new variable called rideStatus like:
status = "arrived at pickup";
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference().child("History");
rootRef.child(requestId).child("rideStatus").setValue(status);
This seems to work for now, but when I need to change the value of rideStatus, hopefully it will work.

Try with this code without push() function:
DatabaseReference arrivedLoc = FirebaseDatabase.getInstance().getReference("History");
String historyId = arrivedLoc.getKey();
arrivedLoc.child(historyId).child("status").setValue("arrived at pickup");
(depends on what you need to achieve on your app, might be a little different)
Update #2:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference().child("History");
addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.exists()){
for(DataSnapshot snapshot : dataSnapshot.getChildren()){
snapshot.getRef().child("status").setValue("arrived at pickup");
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
}

Try with updateChildren():
driverId = FirebaseAuth.getInstance().getCurrentUser().getUid();
HashMap<String, String> newData = new HashMap<>();
newData.put("status", "arrived_loc");
final DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference().child("History/" + driverId); // Or however the path is
rootRef.updateChildren(newData);

Getting Logged in User details from Firebase real time databse

I am using Firebase real-time database and registered user details with Email and Password authentication.
Now, I can successfully do login and logout for registered users.
Now, I have to get details of currently logged in user.
My database structure is as below :
{
"UserInfo : " : {
"User ID : CxQNTJwnoleIk9M1iYMT9TsrJst2" : {
"-Kvb_W0YWX7M8dPF7Kn9" : {
"contact" : "8888888888",
"email" : "visu#gmail.com",
"firstname" : "Vish",
"lastname" : "Mo",
"password" : "vish",
"strUserId" : "CxQNTJwnoleIk9M1iYMT9TsrJst2"
}
},
"User ID : e1VCGeshWfOeptzzj4kP1POtmhk2" : {
"-KvbTM1Jtzn3r9V7II47" : {
"contact" : "9999999999",
"email" : "ja#gmail.com",
"firstname" : "Ja",
"lastname" : "Mo",
"password" : "ja123#",
"strUserId" : "e1VCGeshWfOeptzzj4kP1POtmhk2"
}
}
}
}
For example, If I have logged in with email: visu#gmail.com then I want to get all the details of that user.
How can I do it ??
Ya, I can get Email and Displayname as below :
FirebaseUser user = firebaseAuth.getCurrentUser();
txtUsername.setText("Welcome, " + user.getDisplayName() + "\n" + user.getEmail());
But, I want to get all the details of that user from above-specified database structure. Please, guide me. Thanks.

When you do as this:
FirebaseUser user = firebaseAuth.getCurrentUser();
txtUsername.setText("Welcome, " + user.getDisplayName() + "\n" + user.getEmail());
It's just your Authentication field, not your database.
As first, you should define these field by:
private DatabaseReference mDatabase;
// ...
mDatabase = FirebaseDatabase.getInstance().getReference();
In your db structure:
mDatabase.child("UserInfo : ").child("User ID : CxQNTJwnoleIk9M1iYMT9TsrJst2").child("-Kvb_W0YWX7M8dPF7Kn9").child("contact").getValue();
In the end, refactor your db structure by simple word. UserID, Email, Password is redundant because which can be taken by Authentication Field.
Read more: https://firebase.google.com/docs/database/android/read-and-write

try this. hope this will work
FirebaseUser user = firebaseAuth.getCurrentUser();
FirebaseDatabase.getInstance().getReference().child("UserInfo")
.child(user.getUid())
.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.exists()){
UserClass curUser = dataSnapshot.getValue();
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});

And Finally, I have done as below :
private void showData() {
progressDialog=new ProgressDialog(ProfileActivity.this);
progressDialog.setMessage("Getting data...");
progressDialog.show();
DatabaseReference mDatabase;
mDatabase = FirebaseDatabase.getInstance().getReference().child("UserInfo : ").child("User ID : " + firebaseAuth.getCurrentUser().getUid());
ValueEventListener postListener = new ValueEventListener() {
#Override
public void onDataChange(com.google.firebase.database.DataSnapshot dataSnapshot) {
progressDialog.dismiss();
User user = dataSnapshot.getValue(User.class);
txtFname.setText(user.getFirstname());
txtLname.setText(user.getLastname());
txtEmail.setText(user.getEmail());
txtPassword.setText(user.getPassword());
txtContact.setText(user.getContact());
}
#Override
public void onCancelled(DatabaseError databaseError) {
progressDialog.dismiss();
Toast.makeText(ProfileActivity.this, "Couldn't get data.", Toast.LENGTH_SHORT).show();
}
};
mDatabase.addValueEventListener(postListener);
}
Created a method, in which loaded ProgressDialog first, then took a Database refrence and initialized it up to my databse node with getting UUid from FirebaseAuth instance. Attached ValueEventListener and inside method : onDataChange, used instance of DataSnapshot to get value for my User class. and Finally displayed fetched data to my textviews.
Thanks all for your efforts. upvoted.
EDIT :
My new structure is as below :
{
"UserInfo : " : {
"User ID : I6wWODplkNXqAhSCRZsH6sjf4mM2" : {
"contact" : "9999999990",
"email" : "dhaval#gmail.com",
"firstname" : "Dhaval",
"lastname" : "Patel",
"password" : "dhaval123",
"strUserId" : "I6wWODplkNXqAhSCRZsH6sjf4mM2"
},
"User ID : Nf4kDsxAXYbclt16HahkzsYABWE3" : {
"contact" : "9999999999",
"email" : "bandish#gmail.com",
"firstname" : "Bandish",
"lastname" : "Mehta",
"password" : "bandish123",
"strUserId" : "Nf4kDsxAXYbclt16HahkzsYABWE3"
}
}

Firebase Database ArrayList is not ordered

Why is the list I retrieve from the Firebase Database not ordered with orderByKey()?
DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference();
transactions = mDatabase.child("balance").child("users").child(userid).child("log").orderByKey();
transactions.addValueEventListener(new ValueEventListener() {
public void onDataChange(DataSnapshot snapshot) {
Map<String, Object> td = (HashMap<String,Object>) snapshot.getValue();
ArrayList<Object> values = new ArrayList<Object>();
values.addAll(td.values());
Log.d("Transactions", values.toString());
}
public void onCancelled(DatabaseError databaseError) {
Log.w(TAG, "loadPost:onCancelled", databaseError.toException());
// ...
}
});
The ArrayList "values" is unordered.
This is an example of the structure in json format:
"balance" : {
"users" : {
"log" : {
"-Kp0plO6zBeulHQ8S1Fj" : {
"In" : 100
},
"-Kp0qHM73Mcwbli1gaK6" : {
"Out" : -100
},
"-Kp0qgkORJx5sTi2rUZf" : {
"In" : 100
},
"-Kp1OCdSpUA7SEZhVoPR" : {
"In" : 100
},
"-Kp1OdtuuF6z_zlNj2St" : {
"In" : 100
}
}
}
}

When you retrieve a collection from Firebase, it receives three pieces of information for each child node:
the key of the child
the value of the child
the relative order of the child
When you call snapshot.getValue() in your current code, you tell Firebase to convert this into a Map<String, Object>. Since a Map is unordered, the Firebase client keeps the keys and values but loses the ordering of the children.
To ensure you keep the order, you must use DataSnapshot.getChildren() to process the result:
DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference();
transactions = mDatabase.child("balance").child("users").child(userid).child("log").orderByKey();
transactions.addValueEventListener(new ValueEventListener() {
public void onDataChange(DataSnapshot snapshot) {
ArrayList<Object> values = new ArrayList<Object>();
for (DataSnapshot child: snapshot.getChildren)) {
values.addAll(child.getValue());
}
}

To achieve what you want you need to change this line of code:
transactions = mDatabase.child("balance").child("users").child(userid).child("log").orderByKey();
with
transactions = mDatabase.child("balance").child("users").child(userid).child("log").orderByChild("In");

How to structure my sport manager Firebase database

I'm building a sport manager app that let the users create their own competitions and update the match results to be consults for other participants.
I read a lot about how flat the database (I come from SQL :-) and saw many video tutorials from the Firebase Team.
At this point I have this structure:
{sport-manager :
...
groups : {
"groupId1" : {
competitionId : "competitionId1"
name : "Group A",
type : "LEAGUE"
},
"groupId2" : {
competitionId : "competitionId1"
name : "West playoofs",
type : "PLAYOFFS"
},
...
},
players : {
"playerId1" : {
birthday : 351408600000,
firsName : "Jhon",
lastName : "Doe",
shirtNumber : 0,
teamId : "teamId1"
},
...
},
teams : {
"teamId1" : {
competitionId : "competitionId1"
name : "Team 1",
},
...
},
teamGroupStats : {
"groupId1" : {
"teamId1" : {
goalsAgainst: 0,
goalsFavor: 0,
matchesDraw: 0,
matchesLoss: 0,
matchesPlayed: 0,
matchesWin: 0,
points: 0,
teamName: "Team 1",
},
"teamId2" : {
...
},
...
},
"groupId2" : {
"teamId2" : {
...
},
...
}
...
}
}
This structure let me make queries to populate a ListView adapter with the data of all the teams that are part of a group in this way:
DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference();
Query groupQuery = mDatabase.child("teamGroupStats").child("groupId1")
Or when I have to get the player from determinated team:
Query playersQuery = mDatabase.child("players").orderByChild("teamId").equalTo("teamId1");
So far, so good. My problem come when I have to delete a team from this structure. For avoid integrity problems I use multipath update to delete all.
A team can have one or more players
A team can be part of one or more groups.
With that in mind, I can delete any teams with all his players.
Map<String, Object> deleteMap = new HashMap<>();
deleteMap.put("teams/teamId1", null);
Query playersQuery = mDatabase.child("players").orderByChild("teamId").equalTo("teamId1");
playersQuery.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot playerSnapshot : dataSnapshot.getChildren()){
deleteMap.put("players/" + playerSnapshot.getKey(), null);
}
// Delete all in one call!
mDatabase.updateChildren(deleteMap);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
How I can make a query to get all the paths with "teamId1" has secundary key in the structure "teamGroupStats"?
His this structure good for the use I need?

IMHO your database is very well structured. Regarding your question, you cannot get all paths as you say. What can you do, is to delete data in the same way as you add it. So in order to delete all data i recomand you using this method:
private static void deleteTeam(String teamId) {
Map<String, Object> map = new HashMap<>();
map.put("/teams/" + teamId, null);
map.put("/teamGroupStats/groupId1/" + teamId, null);
map.put("/players/playerId1/teamId/", null);
databaseReference.updateChildren(map);
}
A more generic method will be:
private static void deleteTeam(String reference, String teamId) {
Map<String, Object> map = new HashMap<>();
map.put(reference, null);
databaseReference.updateChildren(map);
}
If you need to query the database to get additional data, use getRef() method to get the reference and pass those values to the second method.
All your data will be deleted at once atomically.
Hope it helps.

Finally I found one solution. I modified my database to store all the groups Id's where the team belong inside the Team structure.
teams : {
"teamId1" : {
competitionId : "competitionId1"
groups : {
"groupId1" : true,
"groupId6" : true,
...
},
name : "Team 1",
},
...
With that information, I can add an inner ValueEventListener in the playersQuery's listener and make the update/delete.
public static void deleteTeam(final String teamId){
Map<String, Object> deleteMap = new HashMap<>();
deleteMap.put("teams/" + teamId, null);
DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference();
Query playersQuery = mDatabase.child("players").orderByChild("teamId").equalTo(teamId);
playersQuery.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot playerSnapshot : dataSnapshot.getChildren()){
String playerId = playerSnapshot.getKey();
deleteMap.put("players/" + playerId, null);
}
mDatabase.child("teams").child(teamId).child("groups")
.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot groupSnapshot : dataSnapshot.getChildren()){
String groupId = groupSnapshot.getKey();
deleteMap.put("teamGroupStats/" + groupId + "/" + teamId, null);
}
// Delete all in one call!
mDatabase.updateChildren(deleteMap);
}
#Override
public void onCancelled(DatabaseError databaseError) {
System.out.println("The read failed: " + databaseError.getCode());
}
});
}
#Override
public void onCancelled(DatabaseError databaseError) {
System.out.println("The read failed: " + databaseError.getCode());
}
});
}
I wasn't very sure about the inner listener, and I had to made a little change to my database structure, but this works fine.
If anybody knows a better way to do this, I'm open to read it. Thanks!