How to delete item from firebase list

Question

I have firebase (realtime database) simple structure like this:

Listing all items in view:

<ion-list>
  <ion-item *ngFor="let item of arrData; let i = index" (click)="delete(item)">
    {{i+1}}. {{item.name}}<small> -  {{item.address}}</small>
  </ion-item>
</ion-list>

In controller the database is defined, because showing and adding data is working:

arrData = []

  constructor(public navCtrl: NavController, private fdb: AngularFireDatabase) {
    this.fdb.list("/schools/").valueChanges().subscribe(data =>{
      this.arrData = data;
      console.log(this.arrData);
    })
btnAddClicked(){
    this.fdb.list("/schools/").push({name:this.schoolName, address:this.schoolAddress});
  }

I want to delete item when it is selected (clicked). From documentation I understand that it is possible to use .remove(), just need path to item. But for that I need to get that auto-generated key. How to get that? Or is there another way to remove selected item?

can you show the output of the line `console.log(this.arrData) ` ? — Umar Hussain, Apr 18 '18 at 09:38

score 1 · Answer 1 · answered Apr 18 '18 at 07:21

Thanks to this post, found solution. Maybe not the prettiest, but works:

delete(item){
    var db = this.fdb.database.ref();
    var query = this.fdb.database.ref("schools").orderByKey();
    query.once("value")
      .then(function(snapshot) {
      snapshot.forEach(function(childSnapshot) {
        var pkey = childSnapshot.key; 
        var chval = childSnapshot.val();

        //check if remove this child
        if(chval.name == item.name && chval.address == item.address){
          db.child("schools/"+pkey).remove();
          return true;
        }

      });
    });
  }

score 0 · Answer 2 · answered Dec 19 '18 at 16:13

I think there is something you need to take in the code. I took to your code snippet to address my concern. The line chval = childSnapshot.val(); should changed to chval =childSnapshot.val with the parenthesis.

deleteNote(key){


 // var db = this.fdb.database.ref();
    var query = firebase.database().ref('todo').orderByKey();
    query.once("value")
      .then(function(snapshot) {
      snapshot.forEach(function(childSnapshot) {
        var pkey = childSnapshot.key; 
        var chval = childSnapshot.val;

        console.log(childSnapshot.val);
        //check if remove this child
        if(chval.note == key.note && chval.date == key.date){
            firebase.database().ref().child("todo/"+pkey).remove();
          return true;
        }

      });
    });
    this.state.noteArray.splice(key, 1);
    this.setState({noteArray: this.state.noteArray});
}

How to delete item from firebase list

2 Answers2