I have a REST API which is written to fetch the questions and answers data for a quiz app that we are working on, and the sql am using is as follows in the API file. I have set the limit as (LIMIT 0,15) as if I change that to 16 there is no data returned by postman. Below are the screenshots for the same.

<?php

include('config.php');

 if (isset($_SERVER['HTTP_ORIGIN'])) {
    header("Access-Control-Allow-Origin: {$_SERVER['HTTP_ORIGIN']}");
    header('Access-Control-Allow-Credentials: true');
    header('Access-Control-Max-Age: 86400');    // cache for 1 day
}

// Access-Control headers are received during OPTIONS requests
if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {

    if (isset($_SERVER['HTTP_ACCESS_CONTROL_REQUEST_METHOD']))
        header("Access-Control-Allow-Methods: GET, POST, OPTIONS");         

    if (isset($_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']))
        header("Access-Control-Allow-Headers:
 {$_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']}");

    exit(0);
  }

 $postdata = file_get_contents("php://input");
 if (isset($postdata)) 
 {
    $request = json_decode($postdata);

    $SubID = $request->SubID;

    if( isset($SubID) ) {
        $select_sql = "SELECT * FROM `questions` WHERE `subjectid` = 
   '".$SubID."'";

        $select_query = mysqli_query($con,$select_sql);
        $count = mysqli_num_rows($select_query);
        if($count>0) {
            while($fetch_obj = mysqli_fetch_array($select_query 
 ,MYSQLI_BOTH)) {

                    $SubId = $fetch_obj["subjectid"];
                    $QuestId = $fetch_obj["questionid"];
                    $QuestType = $fetch_obj["questiontype"];
                    $Quest = $fetch_obj["question"];
                    $Ans1 = $fetch_obj["answer1"];
                    $Ans2 = $fetch_obj["answer2"];
                    $Ans3 = $fetch_obj["answer3"];
                    $Ans4 = $fetch_obj["answer4"];
                    $CorrectAns = $fetch_obj["correctanswer"];
                    $Hint = $fetch_obj["hint"];
                    $DiffLevel = $fetch_obj["difficultylevel"];
                    $Status = $fetch_obj["status"];
                    $AnsDescrip = $fetch_obj["ans_description"];

                    $QuestionsList[] = array( "SubjectID" => "$SubId",
                        "QuestionID" => "$QuestId", 
                        "QuestionType" => "$QuestType", 
                        "Question" => "$Quest",
                        "Answer1" => "$Ans1", 
                        "Answer2" => "$Ans2",
                        "Answer3" => "$Ans3",
                        "Answer4" => "$Ans4",
                        "CorrectAnswer" => "$CorrectAns",
                        "Hint" => "$Hint", 
                        "DiffLevel" => "$DiffLevel",
                        "Status" => "$Status",
                        "AnsDescription" => "$AnsDescrip");

            }
                $json = array("status" => 1, 
                    "message" => "Questions list Successfully fetched", 
                    "QuestionsList" => var_dump($QuestionsList));
               /* foreach ($QuestionsList as $value) {
                    print_r($value);
                }*/
        }
        else {
                $json = array("status" => 0, "message" => "No Records 
Found.", "query" => $select_sql);
        }

    }
}
mysqli_close($con);

header('Content-type: application/json');
echo json_encode($json);

?>

On having the LIMIT 0, 15 in the sql , it returns the data as shown below:

If I remove the LIMIT in the sql it returns nothing, as below.

Does this have something do with the JSON response data limit in php, if yes where can I change this? And also I have checked in on the production live server as well and it returns the same result. Please help me out on this.

on doing a var_dump($QuestionList) :

解决方案

Your query:

$select_sql = "SELECT * FROM `questions` WHERE `subjectid` = 
     '".$SubID."' LIMIT 0, 15";

Without limit:

$select_sql = "SELECT * FROM `questions` WHERE `subjectid` = 
     '".$SubID."'";

In LIMIT 0,15:

• 0 is the offset of the first row.
• 15 is the maximum number rows that return from table.