使用auth查询所有孩子的firebase数据

时间:2016-06-28 03:14:31

标签: angularjs ionic-framework firebase angularfire firebase-realtime-database

我按照this教程制作了一个带有firebase同步和身份验证的应用。但现在,我不知道如何在所有孩子中进行搜索,因为这些孩子都有基于词典编纂的密钥。

更具体地说,从这个例子中,你如何从所有“用户”查询所有“currentCity”

{
  "users" : {
    "1e2f048f-a3a0-4190-afad-81d724ed1997" : {
      "currentCity" : "Arrecifes",
      "currentCountry" : "ARG",
      "currentState" : "BSA",
      "day" : {
        "domingo" : true,
        "jueves" : true,
        "martes" : false,
        "miercoles" : true
      },
      "gender" : "Masculino",
      "name" : "Guillermo H Acosta",
      "position" : "Medio",
      "registered" : true,
      "timeSince" : "22:00",
      "timeUntil" : "23:00",
      "whereToPlay" : "Güemes"
    },
    "39c6ccf9-61ec-446e-9af3-3a87810fab71" : {
      "currentCity" : "Alvear",
      "currentCountry" : "ARG",
      "currentState" : "CRR",
      "day" : {
        "jueves" : true,
        "miercoles" : true,
        "viernes" : true
      },
      "gender" : "Masculino",
      "name" : "Guillermo Acosta",
      "registered" : true,
      "timeSince" : "21:00",
      "timeUntil" : "23:00"
    },
    "4991bdc9-dfc4-4ff5-ab81-0e28f1b3ab53" : {
      "currentCity" : "Cordoba",
      "currentCountry" : "ARG",
      "currentState" : "COR",
      "day" : {
        "miercoles" : true,
        "viernes" : true
      },
      "gender" : "Masculino",
      "name" : "Hsjja",
      "timeSince" : "02:00",
      "timeUntil" : "03:00"
    },
    "509364fd-388b-42ff-91ed-0811811a4ff3" : {
      "day" : {
        "jueves" : true,
        "lunes" : true,
        "martes" : false,
        "sabado" : true
      },
      "name" : "Guillermo Acosta",
      "position" : "Delantero",
      "timeSince" : "13:00",
      "timeUntil" : "14:00",
      "whereToPlay" : "Güemes"
    }
  }
}

2 个答案:

答案 0 :(得分:1)

使用Firebase数据库,您可以获得节点,也可以不获取该节点。无法在查询中获取每个节点的一部分。

因此,如果您只想加载所有用户的城市,则应保留一个仅包含该信息的节点:

{
  "userCurrentCities" : {
    "1e2f048f-a3a0-4190-afad-81d724ed1997" : "Arrecifes",
    "39c6ccf9-61ec-446e-9af3-3a87810fab71" : "Alvear",
    "4991bdc9-dfc4-4ff5-ab81-0e28f1b3ab53" : "Cordoba",
  }
}

答案 1 :(得分:0)

这将解析每个节点抓取currentCity键。如果currentCity为NULLABLE,我建议将其存放在单独的节点中。

let ref = // path to users here
ref.observeEventType(FIRDataEventType.Value, withBlock: { (snapshot) in
    // Put all of the users into a dictionary
    let postDict = snapshot.value as! [String : AnyObject]
    for user in postDict {
        // Set each child of the user as a dictionary
        let data = activity.1 as! [String : AnyObject]

        // Get the specific child
        let currentCity = children["currentCity"] as! String

        // Do something with the data
        print(currentCity)
    }
})