传入String - Firestore - Swift数组的Firestore查询

let collectionRef = Firestore.firestore().collection("collectionName")
let query = collectionRef.whereField("fieldName", isEqualTo: "searchString")

query.getDocuments { (snapshot, error) in
    if let error = error {
        print("Error getting documents: \(error)")
    } else {
        var results = [String]()
        for document in snapshot!.documents {
            results.append(document.data()["fieldName"] as! String)
        }
        print("Results: \(results)")
    }
}