如何比较值和从Firebase实时数据库中删除？

Question

I am using Firebase realtime database in Android app, and have data like this:

How can I access that data from javascript. I just wanna code function to get value of every endTime and compare with current time and if endTime <= Current Time then delete values yellow marked on anther image.

Events is fixed value.

Indjija, Vojvodina and -KsB2mVkpgQe_fRyFFH4 are auto generated so it's possible to have more values like that two.

I know how to solve that in android studio with Java code but I'm interesting about implementing server functions.

Answer 1

The answer to this question is buried deep within Firebase Database Reference . forEach() is used to get to the child without knowing the child's exact path.

var leadsRef = database.ref('leads');
leadsRef.on('value', function(snapshot) {
    snapshot.forEach(function(childSnapshot) {
      var childData = childSnapshot.val();
    });
});

Now childSnapshot will contain the required data, the same thing can also be accessed using child_added .

leadsRef.on('child_added', function(snapshot) {
      //Do something with the data
});

The only difference is that in case of forEach() , it will loop through from the start so if any new data will be added, it will also load the previous data but in case of child_added , the listener is only on new child and not the previous existing childs.

Useful Link:

Firebase Read and Write Web

Hope it helps.