private fun getOrderData(){
    // Query.Direction.DESCENDING 由高至低排序
    db.collection("personalData").orderBy("score",Query.Direction.DESCENDING).limit(3).get()
        .addOnSuccessListener {
            for (eachData in it) {
                Log.v("test__", "${eachData.data}")
            }
            Toast.makeText(this,"讀取成功",Toast.LENGTH_SHORT).show()
        }
        .addOnFailureListener {
            Toast.makeText(this,"讀取失敗",Toast.LENGTH_SHORT).show()
        }
}