Is there a way in Firebase to automatically swap a list of id's into the object

Question

I have a Firebase database with a list of users and a list of best friends, a user's best friends can be pulled by using it's userid:

users list:

userid
- user data
userid
- user data
..

best friends list:

userid
- userid of friend
- userid of friend
- ...
userid
- userid of friend
- userid of friend
- ...
- ...
- ...

Is there a way using the Firebase api to get the friend's data in a list instead of a list of userid's of your friends when making the call to get your best friends ? Now i have to do 2 steps (get best friends id's -> loop users for friend's data)

https://www.youtube.com/watch?v=Idu9EJPSxiY check out this youtube video, what I think from your description is that you want to perform join — Jainam Jhaveri, May 23 '18 at 13:04
Have a look at this answer: https://stackoverflow.com/questions/16638660/firebase-data-structure-and-url/16651115#16651115 — Renaud Tarnec, May 23 '18 at 13:15

score 1 · Accepted Answer · answered May 23 '18 at 13:16

1

No, there is not. There is no way to achieve this. You need to query your data twice, first time to get best friends id's and second to get the actual data of those friends. You cannot get that list in a single step, using a single query..

answered May 23 '18 at 13:16

Alex Mamo

130,605
17
163
193

1

You know the OP only got the privilage to up-vote around the time you posted that comment? – André Kool May 23 '18 at 13:50
@AndréKool No but I'm also voting up. It's a useful question. Thanks! – Alex Mamo May 23 '18 at 14:01

score 0 · Answer 2 · answered May 23 '18 at 13:06

What I think from your description is that you want to perform a join.

There's no official "join" method in the Firebase Database SDK, but you can use multiple listeners to combine data from multiple paths.

https://www.youtube.com/watch?v=Idu9EJPSxiY check out this youtube video it will help

Is there a way in Firebase to automatically swap a list of id's into the object

2 Answers2