您好，我正在为我的快速应用程序实现sqlite3，并且我的要求可以使我的应用程序在线和离线运行，因此我将从实时api获取的数据存储在sqlite表上，因此首先我将向您展示我的代码步骤一步一步
在下面，我将向您显示代码，无论是否在enable中进行互联网连接，我都可以从中获取身份
检查Internet连接代码
func checkNet(){
NotificationCenter.default.addObserver(self,selector: #selector(statusManager),name: .flagsChanged,object:nil)
updateUserInterface()
}
func updateUserInterface() {
if Network.reachability.isReachable == true{
print("Success")
self.clientListData.removeAll()
let fileURL = try! FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false).appendingPathComponent("EOBA.sqlite")
if sqlite3_open(fileURL.path, &db) != SQLITE_OK{
print("error opening database")
return
}
let createTable = "CREATE TABLE IF NOT EXISTS Client_List (id INTEGER PRIMARY KEY AUTOINCREMENT, client_id INTEGER, client_type TEXT, first_name TEXT)"
if sqlite3_exec(db, createTable, nil, nil, nil) != SQLITE_OK{
print("Table Not Created")
return
}
print("Every Thing is Fine")
clientList()
}else{
print("Offline")
self.clientLocalData.removeAll()
let fileURL = try! FileManager.default.url(for: .documentDirectory, in: .userDomainMask, appropriateFor: nil, create: false)
.appendingPathComponent("EOBA.sqlite")
if sqlite3_open(fileURL.path, &db) != SQLITE_OK {
print("error opening database")
}
let queryString = "SELECT * FROM Client_List"
var stmt:OpaquePointer?
if sqlite3_prepare(db, queryString, -1, &stmt, nil) != SQLITE_OK{
let errmsg = String(cString: sqlite3_errmsg(db)!)
print("error preparing insert: \(errmsg)")
return
}
while(sqlite3_step(stmt) == SQLITE_ROW){
let id = sqlite3_column_int(stmt, 0)
let client_id = sqlite3_column_int(stmt, 1)
let client_type = String(cString: sqlite3_column_text(stmt, 2))
let first_name = String(cString: sqlite3_column_text(stmt, 3))
print(id)
print(client_id)
print(client_type)
print(first_name)
//heroList.append(Hero(id: Int(id), name: String(describing: name), powerRanking: Int(powerrank)))
clientLocalData.append(ClientOfflineModel(id: Int(id), client_id: String(describing: client_id), client_type: String(describing: client_type)))
do {
let jsonData = try JSONEncoder().encode(clientLocalData)
let jsonString = String(data: jsonData, encoding: .utf8)!
print(jsonString)
} catch {
print(error)
}
}
self.tblListView.reloadData()
}
}
当用户当时启用Internet时，您可以在我的代码中看到，我正在创建数据库表，然后在调用API之后，现在让我向我展示我的API调用方法名称clientList()
API调用方法
func clientList(){
let preferences = UserDefaults.standard
let uid = "u_id"
let acTkn = "acc_tkn"
let u_ID = preferences.object(forKey: uid)
let A_Token = preferences.object(forKey: acTkn)
let params = ["user_id": u_ID!,"access_token": A_Token!]
print(params)
self.viewMainSpinner.isHidden = false
self.viewSpinnerInner.startAnimating()
Alamofire.request(clientlist, method: .post, parameters: params).responseJSON(completionHandler: {(response) in
switch response.result{
case.success(let value):
let json = JSON(value)
print(json)
let data = json["client_list"]
print(data)
if data == []{
//self.viewNodata.isHidden = false
}else{
data.array?.forEach({ (cList) in
let client_List = ClientList(updated_by: cList["updated_by"].stringValue,client_id: cList["client_id"].stringValue, first_name: cList["first_name"].stringValue,address2: cList["address2"].stringValue,country: cList["country"].stringValue, status: cList["status"].stringValue, address1: cList["address1"].stringValue, created_date: cList["created_date"].stringValue, last_name: cList["last_name"].stringValue, email: cList["email"].stringValue, photo: cList["photo"].stringValue, created_by: cList["created_by"].stringValue,client_type: cList["client_type"].stringValue,phone_number: cList["phone_number"].stringValue,zipcode: cList["zipcode"].stringValue,address3: cList["address3"].stringValue,updated_date: cList["updated_date"].stringValue,city: cList["city"].stringValue,state: cList["state"].stringValue,gender: cList["gender"].stringValue,rtb_reg_number: cList["rtb_reg_number"].stringValue)
let client_id = cList["client_id"].stringValue
let client_type = cList["client_type"].stringValue
let first_name = cList["first_name"].stringValue
print(client_type)
var stmt: OpaquePointer?
let insertQuery = "INSERT INTO Client_List (client_id, client_type, first_name) VALUES (?,?,?)"
if sqlite3_prepare(self.db, insertQuery, -1, &stmt, nil) != SQLITE_OK{
print("Error Binding Query")
}
if sqlite3_bind_int(stmt, 1, (client_id as NSString).intValue) != SQLITE_OK{
let errmsg = String(cString: sqlite3_errmsg(self.db)!)
print("failure binding name: \(errmsg)")
return
}
if sqlite3_bind_text(stmt, 2, client_type, -2, nil) != SQLITE_OK{
let errmsg = String(cString: sqlite3_errmsg(self.db)!)
print("failure binding name: \(errmsg)")
return
}
if sqlite3_bind_text(stmt, 3, first_name, -3, nil) != SQLITE_OK{
let errmsg = String(cString: sqlite3_errmsg(self.db)!)
print("failure binding name: \(errmsg)")
return
}
if sqlite3_step(stmt) == SQLITE_DONE{
print("table Saved Successfully")
}
self.clientListData.append(client_List)
})
self.tblListView.reloadData()
}
self.viewMainSpinner.isHidden = true
self.viewSpinnerInner.stopAnimating()
case.failure(let error):
print(error.localizedDescription)
}
})
}
现在，如您所见，在api调用时，我正在将活动api数据插入数据库表中的数据也已成功插入，但是当Internet连接被禁用时，我正在从表中检索数据，那么我无法正确输出数据，就像低于
首先，我向您显示保存在表上的实际值
预期产量
id: 1
client_id: 2
client_type: Local Authority
first_name: Lorem
我得到的输出
id: 1
client_id: 2
client_type: ��
first_name : ��
有时候我会得到如下输出
id: 1
client_id: 2
client_type: lorem
first_name : lorem
您可以看到在第三列中花了一些时间，我在两个字段中都获得了first_name值
我花了1天半的时间，但仍然没有得到解决方案，请有人帮我
答案 0 :(得分：1)
在绑定之前，您应该将字符串转换为utf8。如下更改您的字符串绑定代码：
if sqlite3_bind_text(stmt, 2, (client_type as NSString).utf8String, -1, nil) != SQLITE_OK{
let errmsg = String(cString: sqlite3_errmsg(self.db)!)
print("failure binding name: \(errmsg)")
return
}
if sqlite3_bind_text(stmt, 3, (first_name as NSString).utf8String, -1, nil) != SQLITE_OK{
let errmsg = String(cString: sqlite3_errmsg(self.db)!)
print("failure binding name: \(errmsg)")
return
}