Ordering data in Firebase - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to order data by a child key in Firebase Realtime Database.

Firebase

firebase.database().ref('users').orderByChild('[1]').on('value', snapshot => { console.log(snapshot.val()); });

Drag options to blanks, or click blank then click option'

Aset

Bpush

Cage

Dremove

Attempts:

3 left

💡 Hint

Common Mistakes

Using Firebase methods like 'push' or 'set' instead of a child key.

Leaving the orderByChild argument empty.

The orderByChild method orders data by the specified child key, such as 'age'.

2fill in blank

medium

Complete the code to order data by key in Firebase Realtime Database.

Firebase

firebase.database().ref('messages').[1]().on('value', snapshot => { console.log(snapshot.val()); });

Drag options to blanks, or click blank then click option'

AorderByValue

BorderByKey

ClimitToFirst

DorderByChild

Attempts:

3 left

💡 Hint

Common Mistakes

Using orderByValue when ordering by keys is needed.

Confusing orderByChild with orderByKey.

The orderByKey method orders data by their keys in Firebase.

3fill in blank

hard

Fix the error in the code to order data by value in Firebase Realtime Database.

Firebase

firebase.database().ref('scores').orderBy[1]().on('value', snapshot => { console.log(snapshot.val()); });

Drag options to blanks, or click blank then click option'

APush

BKey

CChild

DValue

Attempts:

3 left

💡 Hint

Common Mistakes

Using orderByChild or orderByKey when ordering by value is required.

Misspelling the method name.

The correct method to order data by their values is orderByValue().

4fill in blank

hard

Fill both blanks to order data by a child key and limit the results to the first 5 items.

Firebase

firebase.database().ref('products').[1]('price').[2](5).on('value', snapshot => { console.log(snapshot.val()); });

Drag options to blanks, or click blank then click option'

AorderByChild

BlimitToLast

ClimitToFirst

DorderByKey

Attempts:

3 left

💡 Hint

Common Mistakes

Using limitToLast instead of limitToFirst.

Ordering by key instead of child key.

Use orderByChild('price') to order by the 'price' key, and limitToFirst(5) to get the first 5 items.

5fill in blank

hard

Fill all three blanks to order data by a child key, start at a minimum value, and limit the results to 3 items.

Firebase

firebase.database().ref('events').[1]('date').startAt([2]).[3](3).on('value', snapshot => { console.log(snapshot.val()); });

Drag options to blanks, or click blank then click option'

AorderByChild

B'2023-01-01'

ClimitToFirst

DorderByKey

Attempts:

3 left

💡 Hint

Common Mistakes

Using orderByKey instead of orderByChild.

Not using quotes around the date string.

Using limitToLast instead of limitToFirst.

Use orderByChild('date') to order by the 'date' key, startAt('2023-01-01') to start from that date, and limitToFirst(3) to get the first 3 items.