CODEWITHSUNDEEP
firebaseflutterdartfirebase-realtime-database
dartKnightRises
dartKnightRises

Reputation: 905

Fetch specific data from Firebase Realtime Database in Flutter

I want to check if the specific number exists in database so it will fetch the password corresponding to the number or else it will return number does not exist in database in Flutter.

enter image description here

var dbRef = FirebaseDatabase.instance.reference().child("NewUsers");
dbRef.equalTo(numberController.text).once().then((DataSnapshot snapshot){
  if(snapshot.value.isNotEmpty){
    var dbRef = FirebaseDatabase.instance.reference();
    dbRef.child(numberController.text).once().then((DataSnapshot snapshot){
      snapshot.value.forEach((key,values) {
        print(values["Password"]);
      });
    });
  }
  else{
    print("pleasesignup first");
  }
});

After this I'm getting the error Unhandled Exception: NoSuchMethodError: The getter 'isNotEmpty' was called on null

Upvotes: 1

Views: 4252

Answers (2)

Peter Haddad
Peter Haddad

Reputation: 80952

Try the following:

var dbRef = FirebaseDatabase.instance.reference().child("newUsers");
dbRef.orderByKey().equalTo(numberController.text).once().then((DataSnapshot snapshot){
     if(snapshot.value.isNotEmpty){
         var ref = FirebaseDatabase.instance.reference("newUsers");
           ref.child(numberController.text).once().then((DataSnapshot snapshot){
                print(snapshot.value); 
                snapshot.value.forEach((key,values) {
                   print(values["Password"]);
              });
          });
       }
   });

First add a reference to the newUsers and using the query orderByKey().equalTo(numberController.text) and then by doing snapshot.value.isNotEmpty it will check if key exists in the database, if it does retrieve the password.

Upvotes: 4

Muhammad Noman
Muhammad Noman

Reputation: 1366

Try this: 

var dbRef = FirebaseDatabase.instance.reference().child("newUsers");
dbRef.orderByKey().equalTo(numberController.text).once().then((DataSnapshot snapshot){
     if(snapshot && snapshot.value){
         var ref = FirebaseDatabase.instance.reference("newUsers");
         ref.child(numberController.text).once().then((DataSnapshot snapshot){
           print(snapshot.value); 
           snapshot.value.forEach((key,values) {
             print(values["Password"]);
          });
        });
     }
     else{
       print("No Record Found");
     }
 });

Upvotes: 0

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