Firebase realtime database query for specific field-CodePudding

I would like to query a Firebase Realtime Database to find a users account based on their Email.

Here is how I am doing it currently with the User's ID obviously wrong when you don't know the ID.

const userData = (await UsersDatabase.ref(`/Users/oi73WHp4T8LUCgtZzesN`).once('value')).val();

How can I query all of the users to find the account with a specific email.

Here is what the JSON Response looks like:

{
   "userData":{
      "Account Created":1647458347685,
      "Date of Birth":"01/01/1901",
      "Email":"[email protected]",
      "Gender":"male",
      "Name":"Test Account"
   }
}

Here is the updated response from this request:

     const userData = (await UsersDatabase.ref("Users").child("userData").orderByChild("Email").equalTo("[email protected]"));

Here is the response in Postman:

{
    "userData": "https://domain.europe-west1.firebasedatabase.app/Users/userData"
}

All help is welcome!

CodePudding user response：

Assuming the email address is stored in the Email property, you can use a query to find the correct child node of Users with:

UsersDatabase
  .ref("Users")
  .orderByChild("Email")
  .equalTo("[email protected]")

CodePudding user response：

In this line, you are awaiting the Reference itself - not fetching its data:

const userData = (await UsersDatabase.ref("Users").child("userData").orderByChild("Email").equalTo("[email protected]"));

This line should be (fixed the query and shattered for readability):

const userData = (
  await UsersDatabase.ref("Users")
    .orderByChild("Email") // <-- removed .child("userData")
    .equalTo("[email protected]")
    .once('value') // <-- this was missing
).val();

/*
userData will be:

{
  "oi73WHp4T8LUCgtZzesN": { // <- this will be random
    "Account Created":1647458347685,
    "Date of Birth":"01/01/1901",
    "Email":"[email protected]",
    "Gender":"male",
    "Name":"Test Account"
  }
}
*/

Although I would rewrite it like this to unwrap the data:


const foundUsersQuerySnapshot = await UsersDatabase.ref("Users")
  .orderByChild("Email")
  .equalTo("[email protected]")
  .limitToFirst(1)
  .once('value');

let userData = null;
foundUsersQuerySnapshot.forEach(childSnapshot => {
  userData = { ...childSnapshot.val(), _key: childSnapshot.key };
  return true; // <- only return first entry
});

/*
userData will either be null (not found) or:

{
  "_key": "oi73WHp4T8LUCgtZzesN",
  "Account Created":1647458347685,
  "Date of Birth":"01/01/1901",
  "Email":"[email protected]",
  "Gender":"male",
  "Name":"Test Account"
}
*/