Update all occurrences of a particular value to null within the Realtime Database using Firebase Cloud Functions

Question

Update all occurrences of a particular value to null within the Realtime Database using Firebase Cloud Functions

I need to update the values of a specific userID linked to multiple post keys in my database by setting the userID to null. The userIDs are associated with post keys located in the path: posts/ivies/userIDs in my database. Take a look at how the database is structured:

https://i.sstatic.net/FE4ZC.png

To accomplish this, I created a loop to search for the userID and change it to null like so:

exports.wipeData = functions.https.onRequest(async (req, res) => {
 const original = 'ppPXA8MvaSRVbmksof0ByOzTxJ92';
    const snapshot = await admin.database().ref('/posts/ivies/userIDs/');
    console.log((snapshot));

    for (let value in snapshot.val) {
      if (value == original) {
      snapshot.val.set("null")
      }
      else {
        console.log(value)
      }
    }

    res.redirect(303, snapshot.ref.toString());

// [END adminSdkPush]
});

Even though this code executes without errors, it fails to replace 'ppPXA8MvaSRVbmksof0ByOzTxJ92' with 'null' as expected. Any assistance would be greatly appreciated. Thanks!

javascript typescript firebase-realtime-database google-cloud-functions

Answer 1

Answer №1

While your overall approach is on the right track, there are a few glitches that need to be addressed.

Consider implementing this revised solution:

exports.clearData = functions.https.onRequest(async (req, res) => {
  const original = 'ppPXA8MvaSRVbmksof0ByOzTxJ92';
  const ref = admin.database().ref('/posts/ivies/userIDs/');
  const query = ref.orderByValue().equalTo(original);

  const results = await query.once('value');
  const updates = {};
  results.forEach((snapshot) => {
    updates[snapshot.key] = null;
  });

  await ref.update(updates);

  res.status(200).send(JSON.stringify(updates));
})

The key modifications include:

Your snapshot variable needs to fetch data from the database, which is accomplished by using once('value') in my code snippet.
This updated code utilizes a query to target nodes with specific values, making database operations more efficient and cost-effective as your user base expands.
The code consolidates all updates into a single object before sending them to the database in a single transaction.
The inclusion of await in await ref.update(updates) ensures proper execution only after the database writes have been successfully completed.

Answer 2

While your overall approach is on the right track, there are a few glitches that need to be addressed.

Consider implementing this revised solution:

exports.clearData = functions.https.onRequest(async (req, res) => {
  const original = 'ppPXA8MvaSRVbmksof0ByOzTxJ92';
  const ref = admin.database().ref('/posts/ivies/userIDs/');
  const query = ref.orderByValue().equalTo(original);

  const results = await query.once('value');
  const updates = {};
  results.forEach((snapshot) => {
    updates[snapshot.key] = null;
  });

  await ref.update(updates);

  res.status(200).send(JSON.stringify(updates));
})

The key modifications include:

Your snapshot variable needs to fetch data from the database, which is accomplished by using once('value') in my code snippet.
This updated code utilizes a query to target nodes with specific values, making database operations more efficient and cost-effective as your user base expands.
The code consolidates all updates into a single object before sending them to the database in a single transaction.
The inclusion of await in await ref.update(updates) ensures proper execution only after the database writes have been successfully completed.

Answer 3

Answer №2

I don't have much experience with firebase cloud functions, but in typical client-side firebase code val must be called as a function, and you need to wait for the value from a reference. You might want to attempt something like this:

exports.wipeData = functions.https.onRequest(async (req, res) => {
  const original = 'ppPXA8MvaSRVbmksof0ByOzTxJ92';
  const userIDs = await admin.database().ref('/posts/ivies/userIDs/');
  userIDs.once("value", snapshot => {
    var lookup = snapshot.val();
    for (let key in lookup) {
      var value = lookup[key];
      if (key == value) {
        userIDs.child(key).set(null);
      }
    }
    res.redirect(303, userIDs.ref.toString());
  });
});

Answer 4

I don't have much experience with firebase cloud functions, but in typical client-side firebase code val must be called as a function, and you need to wait for the value from a reference. You might want to attempt something like this:

exports.wipeData = functions.https.onRequest(async (req, res) => {
  const original = 'ppPXA8MvaSRVbmksof0ByOzTxJ92';
  const userIDs = await admin.database().ref('/posts/ivies/userIDs/');
  userIDs.once("value", snapshot => {
    var lookup = snapshot.val();
    for (let key in lookup) {
      var value = lookup[key];
      if (key == value) {
        userIDs.child(key).set(null);
      }
    }
    res.redirect(303, userIDs.ref.toString());
  });
});

Update all occurrences of a particular value to null within the Realtime Database using Firebase Cloud Functions

Answer №1

Answer №2

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