Deleting fields in Firebase - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does deleting a field in Firebase Firestore mean?

Deleting a field means removing a specific piece of data from a document without deleting the whole document.

beginner

Which Firebase method is used to delete a field in a Firestore document?

The method is FieldValue.delete(), used inside an update operation to remove a field.

beginner

How do you delete a field named age from a Firestore document in JavaScript?

Use update(docRef, { age: FieldValue.delete() }) to remove the age field.

intermediate

What happens if you try to delete a field that does not exist in a Firestore document?

Nothing changes; Firestore ignores the delete request for a non-existing field without error.

beginner

Why might you prefer deleting a field over deleting the entire document in Firestore?

Deleting a field keeps the document and other data intact, useful when only part of the data needs removal.

Which Firebase function deletes a field from a Firestore document?

A FieldValue.delete()

B deleteField()

C removeField()

D FieldValue.remove()

The correct method to delete a field is FieldValue.delete(), used in update operations.

What happens if you delete a field that does not exist in Firestore?

A Nothing changes

B The document is deleted

C An error is thrown

D The field is created and then deleted

Firestore ignores delete requests for non-existing fields without error or changes.

To delete a field named 'status' in Firestore, which code snippet is correct?

A docRef.deleteField('status')

B deleteField(docRef, 'status')

C remove(docRef.status)

D update(docRef, { status: FieldValue.delete() })

Use update with FieldValue.delete() to remove a specific field.

Deleting a field in Firestore affects which of the following?

A All documents in the collection are deleted

B The entire document is removed

C Only the specified field is removed

D The collection is deleted

Only the specified field is removed; the rest of the document stays intact.

Why is deleting a field useful instead of deleting the whole document?

A It archives the document

B It saves bandwidth and keeps other data

C It deletes the entire collection

D It backs up the document automatically

Deleting a field removes only that data, preserving the rest and saving resources.

Explain how to delete a field from a Firestore document and why you might want to do this.

Think about removing just one piece of data without deleting everything.

What happens if you try to delete a field that does not exist in a Firestore document?

Consider how Firestore handles requests for missing data.