Cloud Firestore CRUD in Flutter - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does CRUD stand for in Cloud Firestore?

CRUD stands for Create, Read, Update, and Delete. These are the four basic operations you can perform on data in Cloud Firestore.

beginner

How do you add a new document to a Firestore collection in Flutter?

Use the add() method on a collection reference. For example: FirebaseFirestore.instance.collection('users').add({'name': 'Anna', 'age': 25});

beginner

What method is used to read a single document from Firestore in Flutter?

Use the doc().get() method. For example: FirebaseFirestore.instance.collection('users').doc('userId').get(); This fetches the document data once.

intermediate

How do you update a document in Firestore without overwriting the entire document?

Use the update() method on a document reference. It changes only the specified fields. Example: docRef.update({'age': 30});

intermediate

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

Deleting a non-existing document does not cause an error. Firestore treats it as a successful operation because the document is effectively gone.

Which Firestore method adds a new document with an auto-generated ID?

A add()

B set()

C update()

D get()

The add() method adds a new document with a unique ID automatically generated by Firestore.

How do you read all documents from a Firestore collection in Flutter?

A doc().get()

B collection().get()

C collection().add()

D doc().update()

Use collection().get() to fetch all documents in a collection at once.

Which method updates only specific fields of a Firestore document?

A set() with merge: true

B add()

C get()

D update()

The update() method changes only the fields you specify without overwriting the whole document.

What does the set() method do if the document already exists?

A Overwrites the entire document by default

B Creates a new document with a new ID

C Deletes the document

D Updates only specified fields

By default, set() replaces the whole document unless you use merge: true.

What is the correct way to delete a document in Firestore using Flutter?

A collection().delete()

B set() with empty data

C doc().delete()

D update() with null values

Use doc().delete() to remove a specific document from Firestore.

Explain the four CRUD operations in Cloud Firestore and how you perform each in Flutter.

Think about how you add, read, change, and remove data in Firestore.

Describe the difference between set() and update() methods in Firestore when modifying documents.

Consider what happens to the document data after each method.