In Firebase when using push() How do I get the unique ID and store in my database

Question

I am pushing data in firebase, but i want to store unique id in my database also . can somebody tell me,how to push the data with unique id.

i am trying like this

  writeUserData() {
    var key= ref.push().key();
    var newData={
        id: key,
        websiteName: this.webname.value,
        username: this.username.value,
        password : this.password.value,
        websiteLink : this.weblink.value
    }
    firebase.database().ref().push(newData);
  }

error is "ReferenceError: ref is not defined"

Answer 1

You can get the key by using the function key() of any ref object

There are two ways to invoke push in Firebase's JavaScript SDK.

1. using push(newObject) . This will generate a new push id and write the data at the location with that id.

2. using push() . This will generate a new push id and return a reference to the location with that id. This is a pure client-side operation .

Knowing #2, you can easily get a new push id client-side with:

 var newKey = ref.push().key();

You can then use this key in your multi-location update.

https://stackoverflow.com/a/36774761/2305342

If you invoke the Firebase push() method without arguments it is a pure client-side operation.

 var newRef = ref.push(); // this does *not* call the server

You can then add the key() of the new ref to your item:

 var newItem = { name: 'anauleau' id: newRef.key() };

And write the item to the new location:

 newRef.set(newItem);

https://stackoverflow.com/a/34437786/2305342

in your case :

writeUserData() {
  var myRef = firebase.database().ref().push();
  var key = myRef.key();

  var newData={
      id: key,
      Website_Name: this.web_name.value,
      Username: this.username.value,
      Password : this.password.value,
      website_link : this.web_link.value
   }

   myRef.push(newData);

}

Answer 2

Firebase v3 Saving Data

function writeNewPost(uid, username, picture, title, body) {
  // A post entry.
  var postData = {
    author: username,
    uid: uid,
    body: body,
    title: title,
    starCount: 0,
    authorPic: picture
  };

  // Get a key for a new Post.
  var newPostKey = firebase.database().ref().child('posts').push().key;

  // Write the new post's data simultaneously in the posts list and the user's post list.
  var updates = {};
  updates['/posts/' + newPostKey] = postData;
  updates['/user-posts/' + uid + '/' + newPostKey] = postData;

  return firebase.database().ref().update(updates);
}

Answer 3

You can get last inserted item id using Promise like this

let postRef = firebase.database().ref('/post');
postRef.push({ 'name': 'Test Value' })
    .then(res => {
        console.log(res.getKey()) // this will return you ID
    })
    .catch(error => console.log(error));

Answer 4

Try this . It worked for me

this.addressRef.push(addressObj).then(res => {
    console.log("address key = " + res.key) ;
});

Here res.getKey() will not work but use res.key to get the latest push ID

Answer 5

It looks like now .push() always returns an Observable. When applied the solutions above I had the following error: "Type 'String' has no compatible call signatures".

That being said, I refer what did work in my case for this new version:

Type 'String' has no compatible call signatures

Answer 6

This worked for me:

 var insertData = firebase.database().ref().push(newData);
 var insertedKey = insertData.getKey(); // last inserted key

See Here: Saving data with firebase.