1
我有一个locations-orders
表看起来像这样的最新变化:火力地堡+斯威夫特:抓住唯一的一个子节点
我只想抓住被添加到该记录的最新订单(不是所有已经在其中的其他订单)。这是我有,这是行不通的(我硬编码的位置顺序键):
static func observeOrders(lId: String, f: @escaping (AppState.Order) ->()) {
FIRDatabase.database().reference(withPath: "locations-orders/5P9TF215PZ3ZV")
.child("orders")
.queryEnding(atValue: nil)
.queryLimited(toLast: 1)
.observe(.childAdded, with: { firebaseSnapshot in
let orderObject = firebaseSnapshot.value as! [String: AnyObject]
print("orderObject")
print(orderObject) // <-------------------- only prints once, never prints again
let order = AppState.Order(
title: orderObject["name"] as! String,
subtitle: orderObject["item_variation_name"] as! String,
createdAt: Date(timeIntervalSince1970: TimeInterval(orderObject["created_at"] as! Int/1000)),
name: "name",
status: AppState.Order.Status.Pending
)
f(order)
})
}
我的查询出了什么问题?