在swift3

Question

我试图将紧急数据解析为紧急结构，但它从不分析条件并进入其他情况。这是我的代码和结构。我在第一行写了一些内容。

   if let emergencyDict = snapshotValue["emergency"]  as? [String:[String:Any]]{
        for (emerId, emerData) in emergencyDict {
            let emer = Emergency.init(emergency: emerData as NSDictionary)
            emergency.append(emer)
        }
    }
    else{
        let emer = Emergency.init(emerg: "" as AnyObject)
        emergency.append(emer)
    }


struct Emergency{
var emer_id: String
var emer_name: String
var emer_phoneNo: String

init(emergency: NSDictionary) {

    if emergency.object(forKey: "id") != nil {
        emer_id = emergency.object(forKey: "id") as! String
    }
    else{
        emer_id = ""
    }
  }
}

Answer 1

问题是[Any]作为类型为[[String:Any]]的数组，如果删除第一个对象，则会得到类型为if let array = snapshotValue["emergency"] as? [Any], let emergencyArrar = Array(array.dropFirst()) as? [[String:Any]] { print(emergencyArray) for emergency in emergencyArray { print(emergency) } } 的数组。所以试试这样。

SELECT 
column1,column2,...
FROM
table
LIMIT offset , count;

Answer 2

你在这一行写错了：

if let emergencyDict = snapshotValue["emergency"]  as? [String:[String:Any]]{

应该是：

if let emergencyDict = snapshotValue["emergency"]  as? [[String:Any]]{

Answer 3

此问题应属于来自firebase数据库的查询。

// you have to get the children in emergency, 
// then get the value(dictionary) of each child
ref.child("emergency").observeSingleEvent(of: .value, with: { (snapshot) in
        let value = snapshot.value as? NSDictionary
        let keys = value?.allKeys // [1, 2, 3 ....]

        for key in keys {
            ref.child("emergency").child(key)..observeSingleEvent(of: .value, with: { (snapshot) in
                 let value = snapshot.value as? NSDictionary
                 // Here is your dictionary
            }
        }


    }) { (error) in
        print(error.localizedDescription)
    }