My main issue is the code bellow works fine for me but it is not optimized, i have a PHP file that contains the following MySQL request :
if("GET_CLIENT" == $action){
$code = $_POST['code'];
$db_data = array();
$sql = "SELECT `nom` , `prenom`, `age` FROM `client` WHERE `code` LIKE '$code'" ;
$result = $conn->query($sql);
$row = $result->fetch_assoc())
echo json_encode($db_data);
$conn->close();
return;}
in my dart application i have the following class Client
:
class Client {
String code;
String nom;
String prenom;
Client({this.code, this.prenom, this.nom });
factory Client.fromJson(Map<String, dynamic> json) {
return Client(
code: json['code'] as String,
nom: json['nom'] as String,
prenom: json['prenom'] as String, ); } }
now to fetch the returned single row from the database i have the following Future
function :
Future<Client> fetchClient(String code) async {
var map = Map<String, dynamic>();
map['action'] = 'GET_CLIENT';
map['code'] = code;
var response = await http.post(uri, body: map);
if (response.statusCode == 200) {
final items = json.decode(response.body).cast<Map<String, dynamic>>();
List<Client> listOfClients = items.map<Client>((json) {
return Client.fromJson(json);
}).toList();
print(listOfClients.first.code);
return listOfClients.first;
} else {
throw Exception('Failed to load data.');
}
}
this works fine for me but i as you can see the Future
function is creating a List of clients and this List of course has only one item so i used return listOfClients.first;
now my question is how to optimize my Future function to return only one client like following :
if (response.statusCode == 200) {
final items = json.decode(response.body).cast<Map<String, dynamic>>();
Client client = .. somthing ??
// instead of List Client
return client; // instead of return listOfClients.first
}
PS: the tittle of this post is a bit confusing any suggestion to change it please edit
If the Get_only_one_situation
method is written correctly, it should return only one value, You only have to decode
it, like this:
const uri = 'http://10.0.2.2/re/App_agent/agent.php';
Future<Situation> fetchOneSituation(String ID) async {
var map = Map<String, dynamic>();
map['action'] = 'Get_only_one_situation';
map['ID'] = ID;
var response = await http.post(uri, body: map);
if (response.statusCode == 200) {
return Situation.fromJson(json.decode(response.body));
// You probably need this
// return Situation.fromJson(json.decode(response.body)['data'])
} else {
throw Exception('Failed to load data.');
}
}
After you updated your question, it became clear to me that you are fetching all sectors using this action Get_only_one_situation
, and this is not preferred.
If the entire table must be fetched, all you need to do is fetch the appropriate item using the firstWhere
method, like this:
Future<Situation> fetchSituation(String ID) async {
var map = Map<String, dynamic>();
map['action'] = 'Get_only_one_situation';
var response = await http.post(uri, body: map);
if (response.statusCode == 200) {
final items = json.decode(response.body).cast<Map<String, dynamic>>();
List<Situation> listOfSituations = items.map<Client>((json) {
return Situation.fromJson(json);
}).toList();
return listOfSituations.firstWhere((item)=>item.ID==item.ID);
} else {
throw Exception('Failed to load data.');
}
}
Of course, I do not recommend this method, because querying on the database is faster than the code in a flutter, Especially with so much data.
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