Delete element from array in Firebase

Question

How to delete an element from array from firebase? I have two arrays - the first one with names and the second one with menu type. With my code, I deleted just from the first array.

  func reloadTableView() {
    guestList.removeAll()
    if let tableId = tableData?.id {
        
        Database.database().reference().child("userInfo").child(uid!).child("tables").child(tableId).child("guestsOnTable").queryOrderedByKey().observe(.value) { (snapshot) in
            if snapshot.childrenCount>0 {
                self.guestList.removeAll()
                
                for guest in snapshot.children.allObjects as![DataSnapshot]{
                    if let guestObject = guest.value as? String{
                        self.guestList.append(guestObject)
                    }
                }
                DispatchQueue.main.async {
                    self.guestsOnTableTableView.reloadData()
                }
            }
        }
        
    }
}

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCell.EditingStyle, forRowAt indexPath: IndexPath) {

    if editingStyle == .delete {

        let guestName = guestList[indexPath.row]

        if let tableId = tableData?.id{
            refGuests = Database.database().reference().child("userInfo").child(uid!).child("tables").child(tableId).child("guestsOnTable")
            refGuests.observe(.value) { (snapshot, error) in

                if let error = error {
                    print(error.description)
                }
                if let guests = snapshot.children.allObjects as? [DataSnapshot] {

                    for (index,guest) in guests.enumerated() {
                        if let guestObject = guest.value as? String {
                            if guestObject == guestName {
                                self.guestList.remove(at: index)
                                self.refGuests.setValue(self.guestList)
                                DispatchQueue.main.async {
                                    self.guestsOnTableTableView.reloadData()
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}

enter image description here

Here is the shot from firebase.

score 0 · Answer 1 · answered Aug 20 '21 at 13:50

It is not fully clear what you are trying to achieve.

Generally speaking you can remove elemets from arrays in firestore using the FieldValue.arrayRemove. https://firebase.google.com/docs/reference/android/com/google/firebase/firestore/FieldValue

See example How to delete object from array in firestore

Delete element from array in Firebase

1 Answers1