How to loop through indexed databse references in Firebase

Question

Below is the code from my front end on selecting players:

$scope.total = 50000000;

 var ref = firebase.database().ref("players");

var ref3 = firebase.database().ref("users").child(uid).child("total");

$scope.players = $firebaseArray(ref);

console.log ($scope.players); 

$scope.picked = [];
$scope.history = [];

$scope.buy = function(player) {
    //remove if already added locally
    var index = $scope.history.indexOf(player);

    if(index>=0){
        $scope.history.splice(index,1);
        return;
    }
    var index2 = $scope.picked.indexOf(player.id);
     if(index2>=0){
         $scope.picked.splice(index2,1);
         return;
     }
    //max 6 allowed
    if($scope.history.length>=6){
        alert('max 6 allowed');
        return;
    }
    if($scope.picked.length>=6){
        alert ('max 6 players');
        return;
    }
    var selected = $scope.history.reduce(function(a,b){
        a[b.position] = (a[b.position] || 0) + 1;
        return a;
    }, {}) || {};

    if(!selected[player.position] || selected[player.position]<2){
        $scope.history.push(player);
        $scope.picked.push(player.id);

    }else{
        alert('You can add only two players per position');

    }
  };

  $scope.getTotal = function(){
    return $scope.history.reduce(function(tot, p){
        tot = tot - p.price;
        return tot;
    }, $scope.total);
  };     


  $scope.saveTeam = function(){

   ref3.set( $scope.picked);       
   $location.path('/mySquad');
   };

This is the database node that is reflected in the scope by the code above:

{
 "players" : [ {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 1,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Yasin 'YB' Amusan",
"position" : "forward",
"price" : 8000000
}, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 2,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Hassan 'Hasi' Akinyera",
"position" : "defender",
"price" : 5000000
}, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 3,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Femi 'Fabio' Awoniyi",
"position" : "defender",
"price" : 9000000
 }, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 4,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Deji 'Dej' Awoniyi",
"position" : "forward",
"price" : 7000000
 }, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 5,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Koye 'K10' Kekere-Ekun",
"position" : "midfielder",
"price" : 9000000
 }, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 6,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Teni 'Teezee' Zacchaeus",
"position" : "hybrid",
"price" : 6000000
 }, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 7,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Bolaji 'Boj' Odojukan",
"position" : "forward",
"price" : 7000000
  }, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 8,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Ernest",
"position" : "defender",
"price" : 6000000
}, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 9,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Samad 'States' Animashaun",
"position" : "midfielder",
"price" : 7000000
  }, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 10,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Zachy Mbadiwe",
"position" : "Forward",
"price" : 10000000
}, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 11,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Laolu 'cutie'",
"position" : "defender",
"price" : 7000000
}, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 12,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Fikayo 'Kyo' Etti",
"position" : "defender",
"price" : 8000000
}, {
"R" : 0,
"Team" : "Industry",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 13,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Efe Tunde-Imoyo",
"position" : "defender",
"price" : 5000000
}, {
"R" : 0,
"Team" : "VGC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 14,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Temi 'Forbes' Afolabi",
"position" : "forward",
"price" : 14000000
 }, {
"R" : 0,
"Team" : "VGC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 15,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Dami Etomi",
"position" : "defender",
"price" : 7000000
 }, {
"R" : 0,
"Team" : "VGC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 16,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Tomi 'Belg' Belgore",
"position" : "defender",
"price" : 8000000
 }, {
"R" : 0,
"Team" : "VGC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 17,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Tobi 'Staxx' Kasali",
"position" : "Hybrid",
"price" : 9000000
}, {
"R" : 0,
"Team" : "VGC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 18,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Bobo",
"position" : "Hybrid",
"price" : 9000000
 }, {
"R" : 0,
"Team" : "VGC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 19,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Ola Adeyemi",
"position" : "defender",
"price" : 5000000
 }, {
"R" : 0,
"Team" : "VGC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 20,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Pekun 'Pyzzle' Odutola",
"position" : "Hybrid",
"price" : 9000000
 }, {
"R" : 0,
"Team" : "VGC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 21,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Oreva 'Revz' Amata",
"position" : "forward",
"price" : 11000000
}, {
"R" : 0,
"Team" : "YMFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 22,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Tenny 'TK' Karim",
"position" : "Forward",
"price" : 5000000
}, {
"R" : 0,
"Team" : "YMFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 23,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Andy Inegbese",
"position" : "Midfielder",
"price" : 5000000
 }, {
"R" : 0,
"Team" : "YMFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 24,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Donald 'DO' Ofik",
"position" : "defender",
"price" : 7000000
}, {
"R" : 0,
"Team" : "YMFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 25,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Emeke 'Mexxo'",
"position" : "midfielder",
"price" : 6000000
}, {
"R" : 0,
"Team" : "YMFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 26,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Ife 'I-Baxx Bakare",
"position" : "midfielder",
"price" : 6000000
}, {
"R" : 0,
"Team" : "YMFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 27,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Gabriel 'Gabby' Inegbese",
"position" : "Hybrid",
"price" : 8000000
 }, {
"R" : 0,
"Team" : "YMFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 28,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Jimi Oyelola",
"position" : "Forward",
"price" : 5000000
 }, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 29,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Chad 'Chadea' Oyefolu",
"position" : "Forward",
"price" : 5000000
}, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 30,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Ekoh 'Starboy' Sagoe",
"position" : "midfielder",
"price" : 15000000
}, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 31,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Tomiwa 'JBET' Jaiyeola",
"position" : "Forward",
"price" : 13000000
}, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 32,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Lemar Chris",
"position" : "defender",
"price" : 9000000
}, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 33,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Olumide 'Olic' Williams",
"position" : "defender",
"price" : 8000000
}, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 34,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Leke 'LVD' Dokomu",
"position" : "midfielder",
"price" : 7000000
}, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 35,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Dola Awosika",
"position" : "defender",
"price" : 5000000
 }, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 36,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Nehemiah 'Memphis'",
"position" : "midfielder",
"price" : 7000000
 }, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 37,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Kola 'Skippo' Ayanwale",
"position" : "midfielder",
"price" : 10000000
 }, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 38,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Milekan 'Mileks'",
"position" : "defender",
"price" : 7000000
 }, {
"R" : 0,
"Team" : "ChadFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 39,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Lanre 'Lavigz' Vigo",
"position" : "hybrid",
"price" : 8000000
 }, {
"R" : 0,
"Team" : "FBGFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 40,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Alfred 'Flyz' Obande",
"position" : "defender",
"price" : 6000000
 }, {
"R" : 0,
"Team" : "FBGFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 41,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Chuka 'Zingy' Azinge",
"position" : "hybrid",
"price" : 6000000
 }, {
"R" : 0,
"Team" : "FBGFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 42,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Osobase 'Oso' Omokhodion",
"position" : "midfielder",
"price" : 10000000
 }, {
"R" : 0,
"Team" : "FBGFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 43,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Arnold Okuguni",
"position" : "defender",
"price" : 7000000
 }, {
"R" : 0,
"Team" : "FBGFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 44,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Ikenna Mbadiwe",
"position" : "defender",
"price" : 6000000
 }, {
"R" : 0,
"Team" : "FBGFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 45,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Moukhtar",
"position" : "forward",
"price" : 8000000
 }, {
"R" : 0,
"Team" : "FBGFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 46,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Chinedu 'Anuxx' Anukwem",
"position" : "forward",
"price" : 8000000
 }, {
"R" : 0,
"Team" : "FBGFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 47,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Tosan 'Mac' Wiltshere",
"position" : "defender",
"price" : 6000000
 }, {
"R" : 0,
"Team" : "FBGFC",
"Y" : 0,
"assists" : 0,
"goals" : 0,
"id" : 48,
"image" : "http://res.cloudinary.com/deji/image/upload/v1489787662/blank_photo_mqvivv.png",
"name" : "Martin Agbaso",
"position" : "forward",
"price" : 5000000
 } ],
"users" : {
"5UBG3yqWnRXe05bByUeASYVbY0l1" : {
  "email" : "john@gamail.com",
  "fullname" : "123456",
  "teamname" : "123456",
  "total" : 0,
  "userName" : "john@gamail.com",
  "week" : 0
},
"AotYBSfTDBhl7vbeWK7WFUh9s3i1" : {
  "email" : "vanessa@yahoo.com",
  "fullname" : "123456",
  "teamname" : "123456",
  "total" : [ 1, 2, 3, 4, 5, 6 ],
  "userName" : "vanessa@yahoo.com",
  "week" : 0
},
"l3J1TVsFNLMi0Oxg6hz4AJpacE53" : {
  "email" : "awoniyideji@yahoo.com",
  "fullname" : "Djflex11",
  "teamname" : "deji awoniyi",
  "total" : [ 1, 1, 5 ],
  "userName" : "awoniyideji@yahoo.com",
  "week" : "no"
}
   }
   }

Each of those numbers represent the id of a player which i have indexed in my database security rules so that each selection by the client's 6 man selection is reflected in the "total" array in the database and then contained in the "$scope.selected" array in the scope.

My issue

My intention is then to iterate through each client's selection and run that iteration through my query below :

    for(let i = 0; i<$scope.history.length;i++){
    return i  
    }
var ref = 
firebase.database().ref("players").orderByChild("id").equalTo(i);
$scope.players = $firebaseArray(ref);

The aim is that the part in the brackets 'insert id number here' is to reflect a a player id.

The code runs perfectly when i manually insert a number directly in the code. However, each client will be selecting 6 numbers randomly. Is there a way to iterate through the selection array so that the respective player ids are reflected at the end of my query each time?

The aim is that the corresponding 6 man team of players will be selected by their ids.

Can you replace the pseudo data structure in your question with the actual JSON of your app? You can get this by clicking the "Export JSON" link in your [Firebase Database console](https://console.firebase.google.com/project/_/database/data). — Frank van Puffelen, Sep 06 '17 at 02:17
Have you tried using `.forEach` to iterate through the firebase list? Also what is `$firebaseArray`? — sketchthat, Sep 06 '17 at 03:52
@FrankvanPuffelen i have edited the question to include the 47 players from the database. — Deji Caleb Awoniyi, Sep 06 '17 at 09:03
@sketchthat $firebaseArray is a method that retruns the data as an array — Deji Caleb Awoniyi, Sep 06 '17 at 13:20
From re-reading your question it sounds like you're looking for the equivalent of `SELECT * FROM players WHERE ID in [4, 8, 15, 16, 23, 42]`. The Firebase Database doesn't support such queries. See my answer here: https://stackoverflow.com/questions/29560088/firebase-equivalent-to-sql-where-in and here on why it's often not needed https://stackoverflow.com/questions/35931526/speed-up-fetching-posts-for-my-social-network-app-by-using-query-instead-of-obse/35932786#35932786 — Frank van Puffelen, Sep 06 '17 at 14:33
@FrankvanPuffelen thanks Frank. I've edited the question to include my full code. I haven't been able to get a code that loops through the array in such a way that that the "i" reflects the 6 numbers in the array. — Deji Caleb Awoniyi, Sep 06 '17 at 15:55

How to loop through indexed databse references in Firebase

0 Answers0