firestore onDelete事件触发其他删除事件

Question

我正在尝试在Firestore上使用OnDelete触发器来实现我的云功能。我有两个集合“警报”和“日志”。 Log对象有一个“alertId”键。我想要做的是删除警报以使用云功能删除所有共同记录日志。

类似的东西：

    exports.deleteLogs = functions.database.instance('my-app').ref('/alerts/{alertId}')
        .onDelete((snap) => {
            snap.ref('logs',ref => ref.where('alertId', '==', alertId)).delete();
    });

Answer 1

您可以在删除Firestore文档时触发功能：

exports.deleteUser = functions.firestore
    .document('alerts/{alertID}')
    .onDelete((snap, context) => {
      // Get an object representing the document prior to deletion
      const deletedValue = snap.data();

      // From there, get the deleted alert's id and delete all logs 
      // with that alertId key
    });