how to make a select query to firebase - angularjs

Question

I am using angularfire.
I have my node in firebase /texts/ and it loos like that:
{ title: 'title', text: 'long text' }
In my service i want to get just the title because i want to show a list of the titles and i don't want to load the texts at this moment because usually are a very long texts.
My service looks like that:
var ref= new Firebase( FBURL+'/texts' );
var sync = $firebase(ref);
var text = sync.$asArray();
this.getTitle = function(){
var deferred = $q.defer();
var titles = [];
text.$loaded().then(function(data){
lodash.forEach(data, function(item){
titles.push({title: item.title});
});
deferred.resolve(titles);
})
.catch(function(err){
$state.go('login');
deferred.reject(err);
});
return deferred.promise;
};
I have noticed that inside the variable text there are all the objects so i get everything included the text. What i want to to is just a select name from texts :)
Thanks

Answer 1

When you access Firebase through most of its APIs, it will always retrieve complete nodes. So you can not tell it to retrieve only a subset of the properties.
That means that if you really only want the titles, you'll have to model your data differently. Right now you have something like this:
posts
-Jas73489342
title: "how to make a select query using firebase"
text: "...."
-Jasa8324023
title: "bicycling the grand canyon"
text: "..."
Those -J things are the keys that Firebase generates when you call push.
In order to be able to retrieve just the titles, you'll need to make sure that there is a node that contains just the titles. So let's split up our posts into two separate nodes: titles and texts.
titles
-Jas73489342: "how to make a select query using firebase"
-Jasa8324023: "bicycling the grand canyon"
texts
-Jas73489342: "...."
-Jasa8324023: "..."
To add a new post to the above structure, you'd do something like:
var ref = new Firebase(FBURL),
titles = ref.child('titles'),
texts = ref.child('texts'),
item = { title: 'Petroglyphs in Albuquerqe', text: '...' };
var newItemRef = texts.push(item.text);
var key = newItemRef.key();
var newTitleRef = titles.child(key).set(item.title);
So we first add the text of the new post to the texts node and then use the same key to add the title under the titles node.
You could also leave the posts node as is, but add a titles node with just the titles. Either way you'll have a node that represents precisely what you want: a list of titles.