How to query data in a flattened Firebase structure? - angularjs

Question

I'm trying to create database for a real estate agency with Firebase. I decide to create a flatten database but I need some help..
(I'm using AngularJS)
Here is a sample of the database :
"city" : {
"Montpellier" : {
"xx2" : true,
"xx3" : true
},
"Teyran" : {
"xx1" : true
}
},
"owners" : {
"xxx1" : {
"lastname" : "Duparc",
"name" : "Jean"
},
"xxx2" : {
"lastname" : "Dupont",
"name" : "Henry"
},
"xxx3" : {
"lastname" : "Wood",
"name" : "John"
}
},
"prices" : {
"xxx1" : 405000,
"xxx2" : 100000,
"xxx3" : 122000
},
"type" : {
"appartment" : {
"xx2" : true
},
"home" : {
"xx1" : true
},
"land" : {
"xx3" : true
}
}
XX1, XX2, XX3 is the refs for each product.
In this database we see that in node Type, there is :
one home(house) : XX1
one apartment : XX2
one land : XX3
The question is : What if I want to list each product with type : Apartment?
Then if I'm able to get the ref of each Apartment, how can I construct the details for this product ?
I mean how can I get the name, last name of the owners, price, city, etc ?

Answer 1

What you've shown in your data structure are the indexes.
You'll typically also have a list with the master copy for each property:
"properties": {
"xx1": {
"city": "Teyran",
"owner": "Jean Duparc",
"price": 405000,
"type": "home",
},
"xx2": {
"city": "Montpellier",
"owner": "Henry Dupont",
"price": 100000,
"type": "apartment",
},
"xx3": {
"city": "Montpellier",
"owner": "John Wood",
"price": 122000,
"type": "land",
}
}
Now with our indexes and the above structure, you can for example look up the apartments with:
ref.child('type').child('apartment').on('value', function(keys) {
keys.forEach(function(keySnapshot) {
ref.child('properties').child(keySnapshot.ref().key()).once('value', function(propertySnapshot) {
console.log(propertySnapshot.val());
});
});
})
To update a property, you'd use a multi-location update. For example to update the owner of xx1:
var updates = {};
updates['/properties/xx1'] = property;
updates['/owners/Jean Duparc/'+id] = null;
updates['/owners/Runfast Webmaster/'+id] = true;
ref.update(updates);