The query Error won't go.

[MadaZZ]

import { Injectable } from '@angular/core';
//import { AngularFireDatabase } from 'angularfire2/database';
import { AngularFireDatabase,FirebaseListObservable } from 'angularfire2/database-deprecated';
import { AngularFireAuth } from 'angularfire2/auth';
import { Observable } from 'rxjs/Observable';
import { AuthService } from '../services/auth.service';
import * as firebase from 'firebase/app';
import { ChatMessage } from '../models/chat-message.model'

@Injectable()
export class ChatService {
user: any;
chatMessages: FirebaseListObservable<ChatMessage[]>;
chatMessage: ChatMessage;
userName: Observable;

constructor( private db: AngularFireDatabase, private afAuth: AngularFireAuth){
this.afAuth.authState.subscribe(auth=>{
//We have set user to auth if it is not undefined or null
if(auth !== undefined && auth !== null){
this.user=auth;
}
});
}

//Function to send message
sendMessage(msg:string){
var timestamp= this.getTimeStamp();
var email= this.user.email;
this.chatMessages=this.getMessages();
this.chatMessages.push({
message: msg,
timeSent: timestamp,
userName: this.userName,
email1: email
});
}

//Function to get timeStamp
getTimeStamp(){
const now = new Date();
const date = now.toLocaleDateString();
const time = now.toLocaleTimeString();
return(date+ ' ' + time);
}

//this function gets message from firebase.
getMessages(): FirebaseListObservable<ChatMessage[]> {
// query to create our message feed binding
return this.db.list('messages', {
query: {
limitToLast: 25,
orderByKey: true
}
});
}
}

Above is my complete chatService code (still corrections required in getTimeStamp() )
But the error in the query won't go. Please help me out asap.

[toufikImk]

I had the same issue but it's solved now:

//change
getMessages in chat.service.ts to be like this
getMessages():FirebaseListObservable<ChatMessage[]>{ return this.db.list('Messages', { query :{ limitToLast:25, orderByKey:true } }); }
// in chat.service.ts and app.module.ts you have to make
import {AngularFireDatabaseModule} from'angularfire2/database';
//look like this
import {AngularFireDatabaseModule} from 'angularfire2/database-deprecated';

[Lertis]

Hi @MadaZZ,
My dependencies are:
"firebase": "5.8.1",
"angularfire2": "5.1.1";

I changed:
return this.db.list('messages', {
query: {
limitToLast: 25,
orderByKey: true
}
});
to:
return this.db.list('messages', ref => ref.orderByKey().limitToLast(25));