firebase-realtime-database

问题 The firebase data structure is { "eventAttendees" : { "fm" : { "1" : "David", "2" : "Alice" } }, "events" : { "fm" : { "date" : "2017-06-16", "name" : "Firebase Meetup" }, "gm" : { "date" : "2017-08-12", "name" : "Meet Linh" } }, "users" : { "1" : { "email" : "david@gmail.com", "name" : "David" }, "2" : { "email" : "alice@gmail.com", "name" : "Alice" }, "10" : { "email" : "khanh@gmail.com", "name" : "Khanh" } } } I want to find all users who go to fm event. Here is my code: let ref = Database

问题 I'm trying to get a dataset of messages out of my firebase database and want the messages sorted by added/timestamp. But for some reason no orderby I put in the code is actually used. I tried doing these 2 things. _messagesRef = FirebaseDatabase.instance.reference().child('messages/'+key); _membersSubscription = _messagesRef .orderByChild('timestamp') .onValue//On valuechange .listen((Event event) => _messagesSubscriptionCallback(event)); _messagesRef = FirebaseDatabase.instance.reference()

问题 I'm trying to get a dataset of messages out of my firebase database and want the messages sorted by added/timestamp. But for some reason no orderby I put in the code is actually used. I tried doing these 2 things. _messagesRef = FirebaseDatabase.instance.reference().child('messages/'+key); _membersSubscription = _messagesRef .orderByChild('timestamp') .onValue//On valuechange .listen((Event event) => _messagesSubscriptionCallback(event)); _messagesRef = FirebaseDatabase.instance.reference()

问题 I'm trying to get a dataset of messages out of my firebase database and want the messages sorted by added/timestamp. But for some reason no orderby I put in the code is actually used. I tried doing these 2 things. _messagesRef = FirebaseDatabase.instance.reference().child('messages/'+key); _membersSubscription = _messagesRef .orderByChild('timestamp') .onValue//On valuechange .listen((Event event) => _messagesSubscriptionCallback(event)); _messagesRef = FirebaseDatabase.instance.reference()

问题 I am trying to add data onto firbase realtime database and retrieve that data on a recyclerview.I am successfully able to do that but when i try to retrieve data from firebase its not happening even-though when i try to print my data on logacat window i am successfully able to do that. MainActivity.java import androidx.annotation.NonNull; import androidx.annotation.Nullable; import androidx.appcompat.app.AppCompatActivity; import androidx.recyclerview.widget.LinearLayoutManager; import

问题 I am trying to add data onto firbase realtime database and retrieve that data on a recyclerview.I am successfully able to do that but when i try to retrieve data from firebase its not happening even-though when i try to print my data on logacat window i am successfully able to do that. MainActivity.java import androidx.annotation.NonNull; import androidx.annotation.Nullable; import androidx.appcompat.app.AppCompatActivity; import androidx.recyclerview.widget.LinearLayoutManager; import

问题 I am trying to add data onto firbase realtime database and retrieve that data on a recyclerview.I am successfully able to do that but when i try to retrieve data from firebase its not happening even-though when i try to print my data on logacat window i am successfully able to do that. MainActivity.java import androidx.annotation.NonNull; import androidx.annotation.Nullable; import androidx.appcompat.app.AppCompatActivity; import androidx.recyclerview.widget.LinearLayoutManager; import

问题 Using the Javascript SDK and this sample firebase database, with an index on "mobile" : test A mobile : "+1234567" B mobile : "+2345678" Now I want to query all nodes with mobile = "+1234567" firebase.database().ref("test").orderByChild("mobile").equalTo("+1234567").once('value', function(snapshot) { console.log(snapshot.val()); }); output : null I asked this exact same question for REST API (resolved) : Firebase Realtime equalTo not working with String like "+123" But can not get it working

问题 Using the Javascript SDK and this sample firebase database, with an index on "mobile" : test A mobile : "+1234567" B mobile : "+2345678" Now I want to query all nodes with mobile = "+1234567" firebase.database().ref("test").orderByChild("mobile").equalTo("+1234567").once('value', function(snapshot) { console.log(snapshot.val()); }); output : null I asked this exact same question for REST API (resolved) : Firebase Realtime equalTo not working with String like "+123" But can not get it working

问题 Using the Javascript SDK and this sample firebase database, with an index on "mobile" : test A mobile : "+1234567" B mobile : "+2345678" Now I want to query all nodes with mobile = "+1234567" firebase.database().ref("test").orderByChild("mobile").equalTo("+1234567").once('value', function(snapshot) { console.log(snapshot.val()); }); output : null I asked this exact same question for REST API (resolved) : Firebase Realtime equalTo not working with String like "+123" But can not get it working