Firebase Query order by 和 start at name [英] Firebase Query order by and start at name

问题描述

我正在制作一个显示餐厅详细信息的幻灯片，每张幻灯片都显示了每家餐厅的详细信息.我正在做什么来获取餐厅名单.初始化时，我按名称获得 10 家餐厅

I working on a slidebox for restaurant details, each slide shows the detail of each restaurant. What I'm doing to get the restaurants list. On initialization, I get 10 restaurants by name

$firebaseArray(ref.orderByChild('name').startAt(name).limitToFirst(limit))

但是每个下一个交换，我最后得到并添加单个餐厅并删除第一个以防止超载.

But one each next swap, I'm getting and adding single restaurant in the end and removing the first one so as to prevent from overloading.

问题是，如果有多个同名餐厅，它无法在交换时加载另一个，它总是得到相同的.我应该做哪些改变来防止这种情况发生?

The issue is, if there are multiple same name restaurants, it's unable to load another one on swap, it always get the same one. What changes should I do to prevent this?

推荐答案

保留您显示的最后一项的 key，然后将其作为第二个参数传递给 startAt().

Keep the key of the last item you show, then pass that in as the second parameter to startAt().

所以:

ref.orderByChild('name').startAt(name, previousLastKey).limitToFirst(limit)

当有多个子项具有相同的 name 值时，查询将从具有您指定的键的子项开始.因此，通过这种方法，第 1 页上的最后一项将成为第 2 页的锚"项，以此类推.

When there are multiple children with the same value for name, the query will start at the one with the key you specified. So with this approach the last item on page 1 becomes your "anchor" item for page 2, etc.

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