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How To Get User Specific Data By UID in Firebase [RTDB]

hirajatamil profile image Raja Tamil ・2 min read

One of the questions I have been asked a lot about Firebase is:

How to get currently logged-in user data from Firebase Real-Time Database?

Let’s see how to do that in action.

I am assuming that you already know how to create a project in Firebase, add an appropriate Firebase Product SDKs, and initialization code to your project.

Recommended: Create A Firebase Project and Get Initialization Code

  • Implement Firebase Authentication
  • Add Logged In User Data
  • Get Logged In User Data
  • Protect User Data Using Security Rules

Implement Firebase Authentication

Add Firebase Auth SDK CDN to your HTML file.

<script src="https://www.gstatic.com/firebasejs/6.6.1/firebase-auth.js"></script>
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Make sure to enable the Email/Password option under the Sign-in Method tab on the Firebase Authentication page.

alt text

Being lazy, I added an email and the password values hardcoded rather than getting them from HTML input elements.

var email = "raja@gmail.com"
var password = "pword1"

async function createNewAccount() {
    try {
        const user = await firebase.auth().createUserWithEmailAndPassword(email, password);
        console.log(user.uid)
    } catch (error) {
        console.log(error.message)
    }
}
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When you invoke createNewAccount() on page load, a brand new Firebase account will be created on the Firebase Authentication page.

alt text

Recommended: FirebaseUI + Vue.js: Build A Complete Social Login Page

Get User Data Using Auth() Object

As soon as a new Firebase account is created, you’re in a logged-in state and user’s auth object is available inside onAuthStateChange() method.

firebase.auth().onAuthStateChanged(user => {<br>  if(user) {
    console.log(user.uid)<br>    console.log(user.email)<br>   }
})
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User’s auth object will have some data about the logged-in user. If you want to add some additional information such as phone and address, you will need to store them into the real-time database.

Recommended
Learn Firebase Storage Quickly [Guide]

Add User Data To The Database

Once userAuth object becomes available, compose a user object with properties like name, phone, address, etc including uid and email from userAuth object.

Then, pass it to the writeUserData() function as an argument.

async function createNewAccount() {
    try {
        const userAuth = await firebase.auth().createUserWithEmailAndPassword(email, password);
        var user = {
            name: "Raja",
            phone: "779797329",
            address: "474 Mercer Drive",
            uid: userAuth.uid,
            email: userAuth.email
        }
        writeUserData(user)

    } catch (error) {
        console.log(error.message)
    }
}
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