java Firebase rest API过滤器查询

Question

我的数据看起来像

{
  "word0" : {
    "level" : "B2",
    "meaning" : [ "Meaning19", "meaning43" ],
    "type" : "Noun",
    "weight" : 0,
    "word" : "word99"
  },
  "word1" : {
    "level" : "C1",
    "meaning" : [ "Meaning19", "meaning43" ],
    "type" : "Noun",
    "weight" : 0,
    "word" : "word99"
  },
  "word10" : {
    "level" : "A2",
    "meaning" : [ "Meaning19", "meaning43" ],
    "type" : "Noun",
    "weight" : 0,
    "word" : "word99"
  }
}

我正在使用curl-get-requesthttps://words-b6651.firebaseio.com/DE-EN.json?orderBy="$key"&print=pretty，我希望获得给定级别的所有单词

是否可以执行类似$key的操作。MongoDB中的“级别”？我怎样才能得到这些数据呢

Answer 1

您可以通过以下方式按属性订购：

https://words-b6651.firebaseio.com/DE-EN.json?orderBy="level"&print=pretty

两个注意事项：

• 你需要add an index to your Firebase security rules：".indexOn": "level"

• JSON中的项目将以不确定的顺序排列，因为JSON本质上是无顺序的。这意味着，REST API中的排序只有在同时过滤数据时才真正有用，例如

  https://words-b6651.firebaseio.com/DE-EN.json?orderBy="level"&equalTo="B2"&print=pretty
  

Answer 2

是的，将curl发送到单词的键路径将返回所有值

https://words-b6651.firebaseio.com/my/path/word10.json?&print=pretty