如何使用 Swift 从 UITableViewCell 中删除 Firebase 中的特定子节点 [英] How can I delete a specific child node in Firebase from UITableViewCell using Swift

问题描述

我有一个 UITableView 看起来像这张图片

I have a UITableView which looks like this image

.

当我滑动删除记录时，我可以从存储它的数组中完全删除它，但我在 Firebase 中访问它以在那里删除它时遇到困难.

When I swipe to delete the record, I can remove it perfectly okay from the array in which it is stored, but I am having difficulties in accessing it in Firebase to delete it there.

对于上面的截图，我的 Firebase 数据库结构如下:

My Firebase database structure is as follows for the above screenshot:

 -KWc7RTuOe5PefiMM2tL
    bodyPart: "Arms"
    exerciseName: "Test 1 "
    userId: "8rHmyTxdocTEvk1ERiiavjMUYyD3"
 -KWcEbpw_f6kxcePY5cO
    bodyPart: "Chest"
    exerciseName: "Test 2 "
    userId: "8rHmyTxdocTEvk1ERiiavjMUYyD3"
 -KWcEdUN49QaJIVf0kwO
    bodyPart: "Legs"
    exerciseName: "Test 3 "
    userId: "8rHmyTxdocTEvk1ERiiavjMUYyD3"
 -KWcFrMSaLKQRxghGHyT
    bodyPart: "Arms"
    exerciseName: "Test 4"
    userId: "8rHmyTxdocTEvk1ERiiavjMUYyD3"

如何访问创建时设置的 autoId 值，例如-KWc7RTuOe5PefiMM2tL"，以便删除该子节点?

How can I access the autoId value which is set when it is created e.g "-KWc7RTuOe5PefiMM2tL" so I can remove that child node?

或者我可以根据登录的 UserId 访问 exerciseName 值吗?

Or alternatively could I access the exerciseName value depending on the UserId that is logged in?

推荐答案

根据 MHDev 已经回答的内容:

Following on from what MHDev has already answered:

func tableView(_ tableView: UITableView, commit editingStyle: UITableViewCellEditingStyle, forRowAt indexPath: IndexPath) {
    if editingStyle == .delete {

        if let exerciseName = exercises[indexPath.row].exerciseName {

            let ref = FIRDatabase.database().reference().child("userExercises")

            ref.queryOrdered(byChild: "exerciseName").queryEqual(toValue: exerciseName).observe(.childAdded, with: { (snapshot) in

                snapshot.ref.removeValue(completionBlock: { (error, reference) in
                    if error != nil {
                        print("There has been an error:(error)")
                    }
                })

            })

        }

        exercises.remove(at: indexPath.row)
        tableView.deleteRows(at: [indexPath], with: .left)
    }
}

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