无法访问Firebase orderByChild查询结果中的值

Question

Using Firebase JS library. Trying to access value in firebase query result with no success:

  var ref = firebase.database().ref(`/listUser/${userId}/`);

  ref.orderByChild('email').equalTo('myemail@myemail.com')
  .once("value", 
  res => {
  console.log(res.val());
  console.log(res.key);
  })

The first console.log returns:

{R74E2nc: {email: "myemail@myemail.com", userKey: "R74E2nc"}}

The second console.log returns the userId that I pass in the reference:

BKjAJm

The value I would like to get is R74E2nc because this is the one I don't know and need for further operations. I tried res.val().key and res.val().userKey but they are undefined.

Database structure is:

"listUser": {
     "BKjAJm": {
        "R74E2nc": {email: "myemail@myemail.com", userKey: "R74E2nc"}
                },
                {
        "x1x22": {email: "my2@my2.com", userKey: "x1x22"}

                }
             } 

How can I access this value "R74E2nc"?

Thank you.

Answer 1

You can try this code, by replacing "value" with "child_added"

 var userz = firebase.database().ref()
    .orderByChild("email")
    .equalTo('myemail@myemail.com')
    .once("child_added", function(snapshot) {
        ...
    });