Query Searches Swift

Question

I've got this code:

func filteredUsers(_ query: String) -> [User] {


    let lowercasedQuery = query.lowercased()
    return users.filter({ $0.fullname.lowercased().contains(lowercasedQuery) || $0.username.contains(lowercasedQuery) })
}

I am getting users from my database that match the searched text (inputted by the user).

The problem is that, since my initial user base has grown, it calls all the users registered and that becomes a very long list.

When I fetch my users

     func fetchUsers() {
        guard let currentUid = AuthViewModel.shared.userSession?.uid else { return }

       
//        COLLECTION_USERS.limit(to: 10).getDocuments { snapshot, _ in
        COLLECTION_USERS.getDocuments { snapshot, _ in
            guard let documents = snapshot?.documents else { return }
            self.users = documents.compactMap({ try? $0.data(as: User.self) }).filter({ $0.id != currentUid })
        }
    }

And use the commented line, it only searches the database for the first 10 users in the list, not for all users. Is there any way where I still search the entire database but only retrieve 10 values that match the query, not only searching for the first 10 users?

Any help would be appreciated, thanks!

@FrankvanPuffelen Sorry about that! Thanks for the answer :) — TheLegend27, Aug 01 '21 at 14:12

score 1 · Accepted Answer · answered Jul 16 '21 at 17:26

You'll want to use a Firestore query, instead of performing the search in your application code. With a Firestore query, the filtering is performed by the database, instead of in your application code.

The simplest way to search is:

let dbQuery = COLLECTION_USERS
    .whereField("fullname", isGreaterThanOrEqualTo: query)
    .whereField("fullname", isLessThanOrEqualTo: query+"\u{F7FF}")

This query searches for documents where the fullname starts with the given value.

A few things to note:

Firestore queries are case-sensitive, so this matches only when the case also matches exactly. You can emulate lower-case queries, by storing the lower-case version of the fullname in a separate file (e.g. fullname_lowercase) and searching on that. For more on this, see Cloud Firestore Case Insensitive Sorting Using Query and Are Cloud Firestore queries still case sensitive?
This query only searches for documents where the fullname starts with the requested value, not where it contains that value in another place. If you want that, consider using a dedicated search engine.

Query Searches Swift

1 Answers1