How to structure friendship data with firebase?

Question

I'm novice with firebase and I try to structure my data to store friendship between users of my app.

My data are structured like this :

    { users: {
        user_1: {
          name: John
        },
        user_2: {
          name: Jack
        },
       user_3: { 
          name: Georges
       },
   }, 
   { friendships : {
      user_1 : {
        user_2: {
            name: Jack
          },
        user_3: {
            name: Georges
      },
      user_3: {
        user_1: {
            name: John
        },
         user_2: {
            name: Jack
        }
    }
}

I don't know if my data structure is OK, but I wonder what is the best way to update a name in the friendships if a user changes his name, how can I easily update the reference in the friendships (brows each node ?) ?

Thank you if someone can help me to understand the right way to do that.

A.

Answer 1

The database structure that you are following is a bit messy and might prove a bit hard to navigate through it, Might i suggest :-

  Users{
    userID_1 : {
      username : “Shelly Morgan”  ,     
      useremail : “[email protected]”
       friends :{
        userID_2 : true,
        userID_3 : true,
        userID_4 : true,
                 } 
           },
    userID_2 : {
     username : “Mikael”  ,     
     useremail : “[email protected]”
       friends :{
        userID_1 : true,
        userID_4 : true,
                 } 
           },
    userID_3 : {
     username : “Lenoard Narish”  ,     
     useremail : “[email protected]”
      friends :{
        userID_1 : true,
        userID_2 : true,
        userID_4 : true,
                 } 
           },
    userID_4 : {
     username : “Rob Stark”  ,     
     useremail : “[email protected]”
      friends :{
         userID_1 : true
                 } 
           }

}

In this manner you only store the userID of friends in that users database, and all you have to do is change the values in only friends_uid node.To retrieve the friends database:-

1.) just hit the friends node of that User

2.) listen for every friends uid,

3.) and hit the database with the desired uid to retrieve database of respective friend

Read the documentation in here for retrieving the data : https://firebase.google.com/docs/database/android/retrieve-data

Answer 2

Your structure is almost good, but I would change the friendships node to this:

    { users: {
        user_1: {
          name: John
        },
        user_2: {
          name: Jack
        },
       user_3: { 
          name: Georges
       },
   }, 
   { friendships : {
      user_1 : {
        user_2: true,
        user_3: true,
      user_3: {
        user_1: true,
        user_2: true
    }
}

This is similar to what Dravidian showed, but depending on how many friends you have, it might be a better idea to not store the users friendslist under the users account details node because if you had 1000+ friends you would have to download 1000 children even if you just wanted to get a single value like his name.