Question

我正在尝试删除FirebaseDB中插入的GeoLocations，如下所示：

    map.setOnMapLongClickListener(new GoogleMap.OnMapLongClickListener() {
        @Override
        public void onMapLongClick(final LatLng latLng) {

            dbRef.child("hora").setValue(ServerValue.TIMESTAMP);    //Executes TIMESTAMP function in firebase server and stores that value
            dbRef.child("hora").addValueEventListener(new ValueEventListener() {    
                @Override
                public void onDataChange(DataSnapshot dataSnapshot) {
                    hora = String.valueOf(dataSnapshot.getValue());    

                    geoFire.setLocation(hora, new GeoLocation(latLng.latitude,latLng.longitude), new GeoFire.CompletionListener() {
                        @Override       //Save geolocation with timestamp in seconds
                        public void onComplete(String key, DatabaseError error) {
                            if (error != null) {
                                Log.v("Informe","There was an error saving the location to GeoFire: " + error);
                            } else {
                                Log.v("Informe","Location saved on server successfully!");
                            }
                        }
                    });
                }

                @Override
                public void onCancelled(DatabaseError databaseError) {

                }
            });
        }
    });
}

在数据库中，这将如下所示：

{
  "geofire" : {
    "1515692377982" : {
      ".priority" : "u1dfw2vsqa",
      "g" : "u2xfw2vsqe",
      "l" : [ 48.25681948174579, 22.430931776762012 ]
    },
    "1515692378159" : {
      ".priority" : "u1dfw2vsqa",
      "g" : "u2xfw2vsqe",
      "l" : [ 48.25681948174579, 22.430931776762012 ]
    }
  },
  "hora" : 1515692378159
}

（我不知道为什么只用一次长按就插入了两次）

我已经搜索了这个，我知道我必须使用云功能，但我必须知道JS，我不太了解它，所以，有人可能想帮我做一个删除数据的功能例如，在火堆中停留超过1小时？

我知道这必须由crontab和HTTPS触发，但我需要先检查该函数是否有效。我发现一些有趣的链接：

Delete items that have been in the DB for 2 hours

Delete old users through crontab and HTTPS

我认为它应该是这两个链接的混合。

Answer 1

最后，我得到了它的工作，所以在这里，如果有人需要谷歌云功能来删除超过一小时前的火力棒数据（这是由带有时间戳的键设置，请查看我的数据模型），现在你可以安排crontab每隔一段时间运行一次HTTPS请求。

'use strict';

const functions = require('firebase-functions');
const admin = require('firebase-admin');
admin.initializeApp(functions.config().firebase); 
const ref = admin.database().ref().child('geofire'); //Path to the child that contains the items you want to delete
const CUT_OFF_TIME = 3600000;   //1 Hour

exports.cleanOldFiles = functions.https.onRequest((req, res) => {
      const now = Date.now();
      const cutoff = now - CUT_OFF_TIME;
      const lastHour = '' + cutoff; //Must be String in order to put it inside .orderByKey().endAt()

      const query = ref.orderByKey().endAt(lastHour);
      return query.once('value').then(snapshot => {
        // create a map with all children that need to be removed
        const updates = {};
        snapshot.forEach(child => {
          updates[child.key] = null;
        });
        // execute all updates in one go and return the result to end the function
        return ref.update(updates);
    });

});

Firebase crontab清理

1 个答案: