Firebase 上的通配符查询? [英] Wildcard query on Firebase?

问题描述

是否可以在 Firebase 上进行通配符查询?例如:

Is it possible to do wildcard queries on Firebase? For example:

https://foo.firebaseio.com/person.json?orderBy="name"&equalTo="Lun*"

推荐答案

我知道已经有一段时间了，但我认为其他人可能会感兴趣.您可以伪造"通配符搜索，例如 foo*(因此基本上您可以搜索以指定字符串开头的值).

I know it's been a while but I thought that others might be interested. You can "fake" a wildcard search for things like foo* (so basically you can search for values beginning with a specified string).

对于 iOS 和Swift 它看起来像这样:

For iOS & Swift it would look like this:

dbReference.child("person").queryOrdered(byChild: "name").queryStarting(atValue: "foo").queryEnding(atValue: "foou{f8ff}").observe(.childAdded) { (snapshot: FIRDataSnapshot) in
    print("(snapshot.key) - (String(describing: snapshot.value))")
}

这样做是使用 name 属性的开始和结束值，其中结束键等于开始 + Unicode 范围内的一个非常高的代码点.因为它在 Unicode 中大多数常规字符之后，所以查询匹配所有以 foo 开头的值.

What this does is using a start and end values for name property where the end key is equal to the start + a very high code point in the Unicode range. Because it is after most regular characters in Unicode, the query matches all values that start with foo.

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