firebase functions check sub child name is exists?

Question

Hello i am trying to write a function that find all username below userid and decide the username already exists or not

my json looks like this

    {
  "ali": {
    "AccessToken": "asdadas",
    "CreatedAt": "2017/12/09",
    "DeletedAt": -1,
    "Email": "sadadada",
    "FirstName": "asdad",
    "LastName": "asdadad",
    "LoginType": 0,
    "Phone": "",
    "ThumbNailUrl": "",
    "UpdatedAt": -1,
    "UserName": "asdada"
  },
  "asdadad": {
    "AccessToken": "asdadas",
    "CreatedAt": "2017/12/09",
    "DeletedAt": -1,
    "Email": "asdadadada",
    "FirstName": "asdada",
    "LastName": "asdada",
    "LoginType": 0,
    "Phone": "",
    "ThumbNailUrl": "",
    "UpdatedAt": -1,
    "UserName": "asdadadada"
  }
}

my functions looks like this

    exports.CheckUserName = functions.https.onRequest((req,res) => {
    const userName = req.query.userName;
    if (userName == "" || userName == null) {
        return res.json({
            result: "UserName can not be null or empty"
        })
    } else {
        // what i have to do in here :(
    }
})

i tried a lot of way but i couldn't do it

Muhammad Saad · Answer 1 · 2017-12-09T19:28:58.140

0

I'm java developer so i'll tell you the logic. you can implement in your javascript

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference().child("userId");

rootRef.addListenerForSingleValueEvent(new ValueEventListener() {
  @Override
  void onDataChange(DataSnapshot snapshot) {
    if (snapshot.hasChild("your username")) {
      // run some code
    }
  }
});

Now you can find all username under id. If exists print something according to your need

If you don't know id you can save all usernames in separate node called usernames and put all usernames in there and always check from there if usernames exists in that node or not. pretty simple :)

edited Dec 09 '17 at 19:28

answered Dec 09 '17 at 19:11

Muhammad Saad

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but there is no column has userId – ALKIN ÇAKIRALAR Dec 09 '17 at 19:18
User id is changing for every person – ALKIN ÇAKIRALAR Dec 09 '17 at 19:18
pass the userId in child as a string ! – Muhammad Saad Dec 09 '17 at 19:20
accprding to your question, you need to find all username below user id so i wrote code for that – Muhammad Saad Dec 09 '17 at 19:22
i cant im searching the username in all users – ALKIN ÇAKIRALAR Dec 09 '17 at 19:22
@ALKINÇAKIRALAR check updated answer – Muhammad Saad Dec 09 '17 at 19:29
cant i find another solution ? because i will check email too i dont know can i use foreach like something for this ? – ALKIN ÇAKIRALAR Dec 09 '17 at 19:45
if you're using firebase authentication you don't need to check email from database .. if already signed up it will not sign up again with same email – Muhammad Saad Dec 09 '17 at 19:46

firebase functions check sub child name is exists?

1 Answers1