如何从UITableViewCell使用Swift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 ，它看起来像这个图像

我的Firebase数据库结构如下所示：

  -KWc7RTuOe5PefiMM2tL 
 bodyPart：Arms
 exerciseName：Test 1
 userId： 8rHmyTxdocTEvk1ERiiavjMUYyD3
 -KWcEbpw_f6kxcePY5cO 
 bodyPart：Chest
 exerciseName：Test 2
 userId：8rHmyTxdocTEvk1ERiiavjMUYyD3
 -KWcEdUN49QaJIVf0kwO 
 bodyPart：腿
 exerciseNameTest 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或者我可以根据 UserId code>登录了吗？

解决方案

下面是MHDev已经回答的问题：

$ p $ func tableView（tableView：UITableView，commit editingStyle：UITableViewCellEditingStyle，forRowAt indexPath：IndexPath）{
如果editingStyle == .delete {

如果让exerciseName = exercise [indexPath.row] .exerciseName {

let ref = FIRDatabase.database（）。reference（）。child（userExercises）
在

snapshot.ref.removeValue（completionBlock：$ {$ b $ ref.queryOrdered（byChild：exerciseName）。queryEqual（toValue：exerciseName）.observe（.childAdded，with： {（错误，参考）
如果错误！= nil {
print（有错误：\（错误））
}
}）

}）
：b


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


I have a UITableView which looks like this image

.

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.

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"

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

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

解决方案

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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