Check if value exists in firebase DB

Question

Is there a method in firebase, which can check if value exist in DB? Firebase has method .exists(), but according to docs it checks only the keys.

I have the followi

Answer 1

This is how I searched for a url value in Firebasebase database on my project:

const searchFirebase = (url, idx) => 
{
     firebase
       .app()
       .database()
       .ref("recipes")
       .orderByChild("url")
       .equalTo(url)
       .once("value", (snapshot) => {
         if (snapshot.exists()) {
           const userData = snapshot.val();
           console.log("exists!", userData);
           document.querySelector(`[data-recipe-id="${idx}"]`)
           .classList.replace('fav-heart', 'unfav-heart'); 
         } else {
           return false; 
         }
       });
}