PHP側の場合、これは、categories配列を取得してjsonを作成する方法です。プリペアドステートメントの場合、これは、達成できる方法です
$success = false;
try {
$DBH = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
$success = true;
}
catch(PDOException $e) {
$response["success"] = 0;
$response["message"] = 'Connection failed: ' . $e->getMessage();
$response["data"]=null;
die(json_encode($response));
}
$query_categories = "SELECT category_name FROM categories";
try{
$sth = $sth->prepare($query_categories );
$success = true;
} catch(PDOException $e) {
$response["success"] = 0;
$response["message"] = 'Prepare failed: ' . $e->getMessage();
$response["data"]=null;
die(json_encode($response));
}
try{
$sth->execute();
$success = true;
} catch(PDOException $e) {
$response["success"] = 0;
$response["message"] = 'Execute failed: ' . $e->getMessage();
$response["data"]=null;
die(json_encode($response));
}
$categories = $sth->fetchAll(PDO::FETCH_COLUMN, 0);/* fetches all categories from db */
/* Output of $query_categories
Array
(
[0] => cat1
[1] => cat2
[2] => cat3
[3] => cat4
)
*/
/* json encode $query_categories
["cat1","cat2","cat3","cat4"]
*/
/* check if categories exist or not*/
if(empty($categories)){
$response["success"] = 0;
$response["message"] = "No categories found";
$response["data"]=null;
die(json_encode($response));
$connection = null;
}
if($success) {
$response["success"] = 1;
$response["message"] = "Kylie";
$response["data"]=$categories;
die(json_encode($response));
$connection = null;
/* output
{"success":0,"message":"Kylie","data":["cat1","cat2","cat3","cat4"]}
*/
} else {
$response["success"] = 2;/* don't where you are setting success to 2*/
$response["message"] = "something went wrong";
$response["data"]=null;
die(json_encode($response));
$connection = null;
}
} else {
$response["success"] = 3;/* don't where you are setting success to 3*/
$response["message"] = "Another brick in the wall";
$response["data"]=null;
die(json_encode($response));
$connection = null;
}
私はJavaが得意ではありませんが、ここにリファレンスJSONを解析してその値を配列に変換する方法
/* store json string in the_json */
JSONObject myjson = new JSONObject(the_json);
JSONArray the_json_array = myjson.getJSONArray("data");