Creating and appending arrays in Firebase-ios-swift

Question

How to create an array in the firebase 3.0 and perform the functions of append and delete in the array

This is the data structure i am looking for:-

1-Us         


        

Answer 1

As the links provided by Ivan explain, arrays are seldom a good idea in a database where multiple users are concurrently adding/changing the data. There also seems to be no need to store the friend list as an array. It's actually more efficient to store it as a set of user ids. That way, you're automatically guaranteed that each user id can be in the set only once.

Users: {
   12345: "Rayega",
   67890: "Morse",
   24680: "Tanya",
   13579: "Julian",
   86420: "Mary",
   97531: "Powers"
},
UserFriends: {
   12345: {
      13579: true,
      86420: true,
      97531: true
   },
   67890: {
      86420: true,
      24680: true,
      97531: true
   }
}

That last structure is called an index and is covered in the Firebase documentation under creating data that scales.