Question

我是firebase的新手，我有我的firebase项目的结构

我希望得到所有对象，并且＃34;感兴趣＆＃34;价值等于＆＃34;男人＆＃34;

我写了这样的代码，让所有对象按interes值排序：

let thisUserRef = URL_BASE.childByAppendingPath("profile")

thisUserRef.queryOrderedByChild("Interest")
     .observeEventType(.Value, withBlock: { snapshot in

     if let UserInterest = snapshot.value!["Interest"] as? String {    
          print (snapshot.key)  
     }
}

但我收到零。

Answer 1

您需要遍历所有键值个人资料

"players":{  
        "524050468":{  
            "name":"Disqualification",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "511471621":{  
            "name":"RedBaron_GR",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "519208358":{  
            "name":"pokefast",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        },
        "501168520":{  
            "name":"mad_2fast4u",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "517090729":{  
            "name":"Tcoglani",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "505935551":{  
            "name":"Ultimate_Spinach_",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "505118732":{  
            "name":"VADOR2",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        },
        "504449266":{  
            "name":"MirageIVS",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        },
        "507177678":{  
            "name":"wolrdofAlexis",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        },
        "501356239":{  
            "name":"drcop",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "516847314":{  
            "name":"MaXiMiLiAn_Gr",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "517675972":{  
            "name":"hell_fighter_gr",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "512160116":{  
            "name":"XmorrayX",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        },
        "507147831":{  
            "name":"xxx_Anti_xxx",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        },
        "500190361":{  
            "name":"laskas",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "503220794":{  
            "name":"Sniker71240",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        },
        "503172799":{  
            "name":"PuNniShZz",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        },
        "504438396":{  
            "name":"Oulamagos1980",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"GRBB",
            "team":2,
            "clanDBID":500063884,
            "platoonID":19752025
        },
        "505065980":{  
            "name":"Fermierdu67",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        },
        "501645375":{  
            "name":"marcus68510",
            "prebattleID":19752025,
            "igrType":0,
            "clanAbbrev":"2DBFL",
            "team":1,
            "clanDBID":500029422,
            "platoonID":19752025
        }
    }

此处_是格式if let allProfiles = snapshot.value as? [String:AnyObject] { for (_,profile) in allProfiles { print(profile); let userInterest = profile["Interest"] } }的密钥，配置文件将是该密钥的元素。

修改：

根据docs查询子值。

尝试KYXA-random string，然后使用我在答案中指定的内部循环

Answer 2

This is a basic query in Firebase. (Updated for Swift 3, Firebase 4)

    let profileRef = self.ref.child("profile")
    profileRef.queryOrdered(byChild: "Interest").queryEqual(toValue: "men")
    profileRef.observeSingleEvent(of: .value, with: { snapshot in

        for child in snapshot.children {
            let dict = child as! [String: Any]
            let name = dict["Name"] as! String
            print(name)
        }
    })

The legacy documentation from Firebase really outlines how to work with queries: find it here

Legacy Firebase Queries

新文档相当薄。

哦，只是指出变量; thisUserNode应该是profileRef，因为它实际上是你查询的内容。

如何通过键值从firebase中检索对象

2 个答案: