Before we get our hands dirty with code, I feel it is necessary to understand how data is stored in firebase. Unlike relational databases, firebase stores data in JSON format. Think of each row in a relational database as a JSON object (which is basically unordered key-value pair). So the column name becomes key and the value stored in that column for one particular row is the value. This way the entire row is represented as a JSON object and a list of these represent an entire database table. The immediate benefit that I see for this is schema modification becomes much more cheaper operation compared to old RDBMS. It is easier to add a couple of more attributes to a JSON than altering a table structure.

here is a sample JSON to show how data is stored in firebase:

{
    "user_base" : {
      "342343" : {
        "email" : "[email protected]",
        "authToken" : "some string",
        "name" : "Kaushal",
        "phone" : "+919916xxxxxx",
        "serviceProviderId" : "firebase",
        "signInServiceType" : "google",
      },
      "354895" : {
        "email" : "[email protected]",
        "authToken" : "some string",
        "name" : "devil",
        "phone" : "+919685xxxxxx",
        "serviceProviderId" : "firebase",
        "signInServiceType" : "github"
      },
      "371298" : {
        "email" : "[email protected]",
        "authToken" : "I am batman",
        "name" : "Bruce Wayne",
        "phone" : "+14085xxxxxx",
        "serviceProviderId" : "firebase",
        "signInServiceType" : "shield"
      }
    },
    "user_prefs": {
      "key1":{
        "data": "for key one"
      },
      "key2":{
        "data": "for key two"
      },
      "key3":{
        "data": "for key three"
      }
    },
    //other structures
  }

This clearly shows how data that we used to store in relational databases can be stored in JSON format. Next let’s see how to read this data in android devices.