[Solved] You wrote this Firestore code to get a document but docSnap.exists is false: const docRef = firestore.collection('users').doc(); const docSnap = await docRef.get(); What is the problem? | GCP

GCP - Cloud Firestore and Bigtable

You wrote this Firestore code to get a document but docSnap.exists is false:

const docRef = firestore.collection('users').doc();
const docSnap = await docRef.get();

What is the problem?

AMissing document ID in doc() causes a reference to a non-existing document.

BYou cannot call get() on a document reference.

CCollection name 'users' is invalid without quotes.

DYou must use firestore.doc() instead of collection().doc().

Step-by-Step Solution

Solution:

Step 1: Check doc() usage
Calling doc() without an ID creates a reference to a new document with an auto-generated ID, but it does not exist yet.
Step 2: Understand get() on new doc reference
Trying to get() returns a snapshot with exists=false because the document does not exist.
Final Answer:
Missing document ID in doc() causes a reference to a non-existing document. -> Option A
Quick Check:
doc() needs ID to get existing document [OK]

Quick Trick: Always provide document ID in doc() to read existing document [OK]

Common Mistakes:

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