Verify whether the username is present in the Firebase database using JavaScript

Using Firebase Function, I have created a function that allows users to complete their profile by adding an entry to the Firebase Realtime Database. Here is an example of how the database structure looks:

{
 users:
  {
    AeknQrtMIyPpC4EQDPNQYvQUxCA3:
     {
       username        :  test
       profilePicture  :  https://url.com/1
     }
    AekyPpC4EQnQrtMIQUxCA3yPpC4v:
     {
       username        :  test2
       profilePicture  :  https://url.com/2
     }
  }
}

This function requires userId, username, and profilePicture as parameters.

When the function is called, I would like to be able to check if the desired username already exists in the database.

Although I have reviewed the documentation provided at the following links, I am facing difficulties in implementing it: https://firebase.google.com/docs/database/web/lists-of-data https://firebase.google.com/docs/reference/js/firebase.database.Query

Thank you for your assistance.

Answer №1

In order to verify the presence of a username:

firebase.database().ref().child("users").orderByChild("username").equalTo(username_here).on("value", function(snapshot) {
if (snapshot.exists()) {
     console.log("Username exists in database");
}else{
    console.log("Username does not exist");
  }
});

For further information, visit:

https://firebase.google.com/docs/reference/js/firebase.database.DataSnapshot#exists

Similar questions

If you have not found the answer to your question or you are interested in this topic, then look at other similar questions below or use the search

Vue project encounters disappeared DOM element

I'm currently developing a code typer, but I've encountered an issue where the element inexplicably turns into Null. Despite having some experience with Vue from my previous project on Django/Python at (live preview), I find myself struggling to ...

Creating a directive in AngularJS to automatically populate select options with custom values

As someone who is relatively new to creating directives, I am looking to develop a directive that will assist me in my application. What I aim to achieve is a select element directive that comes pre-populated with options and is self-contained. All I need ...

The JQuery datepicker fails to display the current date

I am experiencing an issue with the datepicker on my webpage. While it is working correctly, the default date being displayed is '01/01/2001' instead of '11/23/2012', as I intended. Here is the jquery code I am using: $(":inpu ...

An unanticipated issue has occurred: TypeError - the product information being searched for is not defined

import { useContext, useEffect, useState } from "react" import Layout from "../components/Layout" import { ProductsContext } from "../components/ProductsContext" export default function CheckoutPage(){ const {selecte ...

The integration of <form> with jQuery Ajax error

I have come across this HTML form function FormSubmit (){ $.ajax({ url:'dotar.php', type:'post', data:$('form').serialize(), success:function(){ setTi ...

Uploading several files with Laravel and Vue JS in one go

Recently, I have been working on a project where I need to upload multiple image files using Vue JS in conjunction with Laravel on the server side. This is the snippet from my Vue template: <input type="file" id = "file" ref="f ...

Retrieve data from cookies that have been stored by the node server on the front end

I am currently utilizing the Node package 'cookie' to establish cookies from the backend as shown below: res.setHeader('Set-Cookie', cookie.serialize('token', token, { maxAge: 60 * 60 * 24 * 7 // 1 week ...

Formatting numbers in JavaScript objects

I am looking to iterate through an array of objects and convert the string values into numbers. Here is a sample scenario: I have data in a format similar to the variable provided below. When passing this array to a kendo chart, it seems to have trouble r ...

Enhance your React Routing using a Switch Statement

I am currently developing a React application where two distinct user groups can sign in using Firebase authentication. It is required that each user group has access to different routes. Although the groups share some URLs, they should display different ...

Quick question about utilizing Ajax with spans

<span name = "menu"> <!-- javascript here --> <!-- content loaded via ajax --> </span> <span name = "content"> <!-- content loaded via ajax --> <!-- updated by buttons from the menu--> </span> Seeking a ...

jQuery: Function is not running as expected

I'm facing a challenge in executing a function twice, and I'm having trouble identifying the issue. Check out my JSFiddle at the following link: http://jsfiddle.net/g6PLu/3/ Javascript function truncate() { $(this).addClass('closed&apo ...

Scrolling to zoom in on the div content

I need the ability to resize the content within a div without changing the size of the div itself when the user scrolls. The function I currently have is as follows: var zoomable = document.getElementById('zoomable'), zX = 1; window.addEvent ...

Expand all nodes by default in React Sortable Tree

Currently working on a React project and incorporating react-sortable-tree. One problem I'm facing is the lack of an option to automatically expand all nodes by default. Does anyone have any suggestions on how to achieve this? Edit: The options "e ...

Utilizing JSON format, handling special characters, and storing data in a database

My friend approached me with a question and although I wanted to offer immediate help, I realized that seeking advice from others may provide better solutions. Situation: Imagine there is a Form that includes a RichText feature: DHTMLX RichText (). This R ...

Retrieve information from an SQL database using user input in a Classic ASP form without the need to refresh the page

Currently, I am in the process of incorporating a new function into an existing Classic ASP system. This feature involves allowing users to scan a barcode that will automatically populate a text field within a form inside a bootstrap modal. The scanner has ...

Unable to retrieve information using the post method in Express framework

After creating a basic code to fetch data from the client, I am facing an issue where req.body.firstname is showing as undefined. Here is the code snippet: const express = require('express'); const app = express(); const body ...

Error: AJAX responseText Mismatch detected

When I make an AJAX call in my code, everything seems to be working correctly. The PHP script responds with "success" when it should, and the response text is indeed "success". However, even though the output appears to be correct, the line if(returnVal == ...

Styling the file input type in AngularLearn how to customize the

I've come across numerous queries on how to style an input type file, but I'm struggling to implement it in an angular context. So, what is the best way to customize the appearance of an input type file within an angular application? Below is t ...

Is there a way to modify the style within a TS-File?

I've created a service to define different colors and now I want to set separate backgrounds for my columns. However, using the <th> tag doesn't work because both columns immediately get the same color. Here's my code: color-variatio ...

Having trouble retrieving the value from the input field with Angular.js

I am having trouble retrieving the value from an input field using Angular.js. Below is the code explanation. Here is my controller code: $scope.shipping=0; $scope.addProductInfoData=function(billdata){ console.log('valid',$scope.shippi ...