firebase-database Getting started with firebase-database Writing simple value into database

Example

First, complete the installation and setup to connect your app to Firebase. Then from anywhere in your class, you can write:

// Write a message to the database
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("message");

myRef.setValue("Hello, World!");

It will write Hello, Wold! into message node, like seen below:

"your-project-parent" : {
    "message" : "Hello, World!"
}

Explanation

FirebaseDatabase database = FirebaseDatabase.getInstance();

Above code will assign FirebaseDatabase instance into database object for further use.

DatabaseReference myRef = database.getReference("message");

Above code will reference myRef object into "message" child of your project's parent (in this example, it is "your-project-parent"). So it is "your-project-parent/message"

myRef.setValue("Hello, World!");

Above code will set "Hello, World!" into path referenced by myRef