Hoi, I would like to check, using React javascript, if a collection in the Firestore already exists, no matter if it’s empty or not. I tried:
if (collection(db, ref)) // is always true somehow
Any ideas? Thanks!
Hoi, I would like to check, using React javascript, if a collection in the Firestore already exists, no matter if it’s empty or not. I tried:
if (collection(db, ref)) // is always true somehow
Any ideas? Thanks!
3
Answers
You would need to try to fetch from the collection and see if anything is returned:
There is no function available in the SDK that can help you can check if a particular collection exists. A collection will start to exist only if it contains at least one document. If a collection doesn’t contain any documents, then that collection doesn’t exist at all. So that being said, it makes sense to check whether a collection contains or not documents. In code, it should look as simple as:
One thing to mention is that I have used a call to
limit(1)
because if the collection contains documents, then we limit the results so we can pay only one document read. However, if the collection doesn’t exist, there is still one document read that has to be paid. So if the above query yields no resul## Heading ##t, according to the official documentation regarding Firestore pricing, it said that:You have to fetch the collection out of the database and check if it has more than 0 documents. Even, if the collection doesn’t exist, it will return 0.