Vue.js。Firebase查询-如何从查询中获取结果？

我有一个Firebase实时数据库，只有一个测试值

{
"details": {
     "uid": "mayU7Zyc3GMC4STXB6mVu32xFO13",
     "honorificPrefix": "Mr.",
     "givenName": "Yves",
     "familyName": "Dufour",
     "address1": "3, chemin des buis",
     "address2": "Les Ballans",
     "zipcode": "16600",
     "city": "Mornac",
     "country": "France"
 }
}

我正在尝试从vue组件获取此测试值

 getUserDetail ({commit}, payload) {
    console.log('ACTION: getUserDetail db: ', payload.db)
    console.log('ACTION: getUserDetail id: ', payload.uid)
    payload.db.ref('details').orderByChild('uid').equalTo('uid', payload.uid).once('value', (snapshot) => {
    // db.ref('details').orderByChild('userId').once('value', (snapshot) => {
      console.log('SNAPSHOT VAL ', snapshot.val())
    })
  }

运行它，我可以访问详细信息，但实际上无法获得预期的结果

console.log('SNAPSHOT VAL ', snapshot.val()) // is null

以下是Firebase的控制台日志输出

ACTION: getUserDetail db:  Database {repo_: Repo, root_: Reference, INTERNAL: DatabaseInternals}INTERNAL: DatabaseInternals {database: Database}app: (...)repo_: Repo {repoInfo_: RepoInfo, app: FirebaseAppImpl, dataUpdateCount: 1, statsListener_: null, eventQueue_: EventQueue, …}root_: Reference {repo: Repo, path: Path, queryParams_: QueryParams, orderByCalled_: false}__proto__: Object
root.js?f07d:131 


ACTION: getUserDetail id:  mayU7Zyc3GMC4STXB6mVu32xFO1


[FIREBASE]  getToken() completed. Creating connection. 
main.js?1c90:62 [FIREBASE]  c:0:0: Connection created 
main.js?1c90:62 [FIREBASE]  c:0:0:0 Websocket connecting to xxxxxxxxxxx
main.js?1c90:62 [FIREBASE]  c:0:0:0 Websocket connected. 
main.js?1c90:62 [FIREBASE]  c:0:0: Realtime connection established. 
main.js?1c90:62 [FIREBASE]  p:0: connection ready 

[FIREBASE]  p:0: Listen on /details for default

......
main.js?1c90:62 [FIREBASE]  p:0: handleServerMessage d {"p":"details","d":{"address1":"3, chemin des buis","address2":"Les Ballans","city":"Mornac","country":"France","familyName":"Dufour","givenName":"Yves","honorificPrefix":"Mr.","uid":"mayU7Zyc3GMC4STXB6mVu32xFO13","zipcode":"16600"}} 

main.js?1c90:62 [FIREBASE]  event: /details:value:{"address1":"3, chemin des buis","address2":"Les Ballans","city":"Mornac","country":"France","familyName":"Dufour","givenName":"Yves","honorificPrefix":"Mr.","uid":"mayU7Zyc3GMC4STXB6mVu32xFO13","zipcode":"16600"} 

[FIREBASE]  event: /details:value:null 
 SNAPSHOT VAL  null

我的问题出了什么问题？这是我的第一个。。。。找不到匹配的好示例

更新

我还尝试了以下查询

payload.db.ref('details').orderByChild('uid').equalTo(payload.uid).once('value', (snapshot) => { 

但是我得到了一个错误

    vue.runtime.esm.js?ff9b:1737 Error: Query.equalTo failed: First argument contains undefined in property 'details'
        at validateFirebaseData (index.cjs.js?8c4d:1432)
        at validateFirebaseDataArg (index.cjs.js?8c4d:1420)
        at Query.equalTo (index.cjs.js?8c4d:5004)
        at Store.getUserDetail (root.js?f07d:132)
        at Array.wrappedActionHandler (vuex.esm.js?358c:704)
        at Store.dispatch (vuex.esm.js?358c:426)
        at Store.boundDispatch [as dispatch] (vuex.esm.js?358c:332)
        at VueComponent.userDetails (eval at ./node_modules/cache-loader/dist/cjs.js?{"cacheDirectory":"/Users/yves/Developments/WIP/VUE.JS-vcli-3-beta/le-choro-des-charentes/node_modules/.cache/cache-loader"}!./node_modules/babel-loader/lib/index.js!./node_modules/vue-loader/lib/selector.js?type=script&index=0!./src/components/Member/Section1.vue (1.js:7), <anonymous>:154:19)

因此，现在我需要基于user.id作为键来生成user.detail对象

我试过了

 payload.db.ref('details').child(payload.uid).once('value', (snapshot) => {
     console.log('SNAPSHOT VAL ', snapshot.val())
 })

但是没有成功

当我查询familyName时，我可以很好地运行它

payload.db.ref('details').orderByChild('familyName').equalTo('Doe').once('value', (snapshot) => {.. }

它应该是.equalTopayload.uid，而不是equalTo'uid'，payload.uid

解决

使用user.uid作为密钥更新结构后，我需要使用

payload.db.ref('details').orderByKey().equalTo(payload.uid).once('value', (snapshot) => {... }

如果我想查询一个值，即familyName，我将使用：

payload.db.ref('details').orderByChild('familyName')
       .equalTo('Doe').once('value', (snapshot) => {... }

---

谢谢我也试过了。请参见问题中的“我的更新”。。我得到一个错误：第一个参数在属性“details”中包含未定义的内容。我想我必须更改DB结构，并用这个更新的结构重新表达我的问题。。。见相关更新2

payload.db.ref('details').orderByKey().equalTo(payload.uid).once('value', (snapshot) => {... }

payload.db.ref('details').orderByChild('familyName')
       .equalTo('Doe').once('value', (snapshot) => {... }