苦苦于将值正确插入数据库

Question

I want use a multi-dimensional array in this format: value[n][], where n is the question number. With this new setup, you should end up with the following input fields:

<input type="hidden" value="A" name="value[1][]">
<input type="hidden" value="B" name="value[1][]">
<input type="hidden" value="A" name="value[2][]">
<input type="hidden" value="C" name="value[2][]">
<input type="hidden" value="E" name="value[2][]">

Note that the selected value is encoded in the value attribute. The name attribute only contains the question to which the value belongs.

So what the above inputs are stating is this:

question 1: answer: A
question 1: answer: B
question 2: answer: A
question 2: answer: C
question 2: answer: E

I want to insert these details into "Question" and "Answer" database tables below:

Question Table:

SessionId    QuestionId

MUL             1
MUL             2

Answer Table:

 AnswerId (auto)  SessionId  QuestionId   Answer
 1                MUL        1            A
 2                MUL        1            B
 3                MUL        2            A
 4                MUL        2            C
 5                MUL        2            E

Now I have attempted writing the mysqli/php code below to insert these values into the database but I am receiving errors and failing badly in wanting to acheive what I want to achieve. I need help being able to correctly insert the correct values in the relevant tables.

Below is the php/mysqli code:

var_dump($_POST);  

$i = 0;
$c = count($_POST['numQuestion']);

for($i = 0;  $i < $c; $i++ ){

/*
    switch ($_POST['gridValues'][$i]){

    case "3": 
    $selected_option = "A-C";
    break;

    case "4": 
    $selected_option = "A-D";
    break;

    case "5": 
    $selected_option = "A-E";
    break;

    default:
    $selected_option = "";
    break;

    }   

    */ needed later on when I insert grid values   



$results = $_POST['value'];
foreach($results as $id => $value) {
$answer = implode(':', $value);

 $questionsql = "INSERT INTO Question (SessionId, QuestionId) 
    VALUES (?, ?)";

    $sessid =  $_SESSION['id'] . ($_SESSION['initial_count'] > 1 ? $_SESSION['sessionCount'] : '');


    if (!$insert = $mysqli->prepare($questionsql)) {
      // Handle errors with prepare operation here
    }

$insert->bind_param("si", $sessid, $id);

        $insert->execute();

        if ($insert->errno) {
          // Handle query error here
        }

        $insert->close();

        $lastID = $id->insert_id;

        foreach($value as $answer) {

         $answersql = "INSERT INTO Answer (SessionId, QuestionId, Answer) 
    VALUES (?, ?)";

      if (!$insertanswer = $mysqli->prepare($answersql)) {
      // Handle errors with prepare operation here
    }  

    $insertanswer->bind_param("sis" $sessid, $lastID, $answer);

        $insertanswer->execute();

        if ($insertanswer->errno) {
          // Handle query error here
        }

        $insertanswer->close();


}

}

}

The var_dump($_POST) outputs this below:

array(3) {
["numQuestion"]=> array(2) { 
  [0]=> string(1) "1" 
  [1]=> string(1) "2" }
["submitDetails"]=> string(14) "Submit Details"
["value"]=> array(4) { 
  ["answerARow"]=> string(1) "A" 
  ["answerCRow"]=> string(1) "C" 
  ["answerBRow"]=> string(1) "B" 
  ["answerERow"]=> string(1) "E" }
}

Below are the errors I am receiving and the line of code each error is linked to:

Warning: implode(): Invalid arguments passed in /.../ on line 226

$answer = implode(':', $value);

Notice: Trying to get property of non-object in /.../ on line 250

$lastID = $id->insert_id;

Warning: Invalid argument supplied for foreach() in /.../ on line 252

foreach($value as $answer) {

Warning: mysqli_stmt::execute(): (23000/1062): Duplicate entry 'MUL-0' for key 'PRIMARY' in /.../ on line 242

The Above Error Points to the $insert query

MORE INFO:

The structure I really want to acheive after posting the text inputs is below:

array(2) { 
            ["numQuestion"]=> array(2) { 
                                        [0]=> string(1) "1" 
                                        [1]=> string(1) "2" 
                                       }
           ["submitDetails"]=> string(14) "Submit Details" 
           ["1"] => array(2) {
                                        [0] => string(1) "A"
                                        [1] => string(1) "C"
                                      }
           ["2"] => array(2) {
                                        [0] => string(1) "A"
                                        [1] => string(1) "B"
                                        [2] => string(1) "E"
                                      }
        }

When the user posts the text input values, it should insert the question numbers and the answers which belongs to their relevant question number.

Answer 1

A few things:

1. $result / $_POST['value'] is a one-dimensional array, so $value in your foreach loop is a string that you cannot use implode on;
2. $lastID = $id->insert_id; should be $insert->insert_id and I'm not sure if you can close the connection already before you call that statement;
3. $value is a string (see first point) so you cannot use foreach there (third warning).