Updating specific fields in Firebase - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does it mean to update specific fields in Firebase?

It means changing only certain parts of a document without replacing the whole document. This keeps other data safe and unchanged.

beginner

Which Firebase method is used to update specific fields in a document?

The update() method is used to change only the fields you want in a document.

intermediate

What happens if you try to update a field that does not exist in Firebase?

Firebase will add the new field with the value you provide. It does not require the field to exist beforehand.

intermediate

How do you update nested fields in Firebase documents?

Use dot notation like "address.city": "New York" inside the update() method to change nested fields.

beginner

Why is updating specific fields better than overwriting the whole document?

It saves data by not touching unchanged fields, reduces errors, and is faster because less data is sent and processed.

Which Firebase method updates only certain fields in a document?

A set()

B delete()

C update()

D get()

The update() method changes only specified fields without replacing the whole document.

What happens if you update a field that does not exist yet in Firebase?

A Firebase adds the new field

B Firebase ignores the update

C Firebase deletes the document

D Firebase throws an error

Firebase adds the new field with the given value if it does not exist.

How do you update a nested field called 'city' inside 'address' in Firebase?

A "address": {"city": "New York"}

B "address.city": "New York"

C "city.address": "New York"

D "city": "New York"

Use dot notation "address.city" to update nested fields.

Which method replaces the entire document in Firebase?

A listen()

B update()

C get()

D set()

The set() method replaces the whole document unless used with {merge: true}.

Why is updating specific fields preferred over overwriting the whole document?

A It keeps unchanged data safe

B It is slower

C It deletes old data

D It requires more data transfer

Updating specific fields keeps other data safe and reduces data transfer.

Explain how to update specific fields in a Firebase document and why it is useful.

Think about changing only parts of a document without touching the rest.

Describe the difference between update() and set() methods in Firebase when changing document data.

Consider what happens to the whole document in each method.