为什么在将数据插入数据库时​​会复制答案？

Question

我将值插入“问题”和“答案”表中。现在的问题表是罚款，如果我插入2个问题，然后它会显示该表所示：

SessionId (PK) QuestionId(Pk) QuestionContent 

RZC    1    Name 2 things you will find with a computer 
RZC    2    Name three things you will find in a toolbox 

但“答案”表原因造成的问题，它复制了答案插入时，该表目前看起来象下面这样：

AnswerId (auto PK) SessionId QuestionId Answer 
1     RZC   1   A 
2     RZC   1   C 
3     RZC   2   A 
4     RZC   2   B 
5     RZC   2   E 
6     RZC   1   A 
7     RZC   1   C 
8     RZC   2   A 
9     RZC   2   B 
10     RZC   2   E 

表应该如下：

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

为什么重复的答案？

下面是PHP和mysqli的代码：

<?php 

    var_dump($_POST); 


    // Prepare your statements ahead of time 
    $questionsql = 'INSERT INTO Question (SessionId, QuestionId, QuestionContent) VALUES (?, ?, ?)'; 
    if (!$insert = $mysqli->prepare($questionsql)) { 
     // Handle errors with prepare operation here 
     echo __LINE__.': '.$mysqli->error; 
    } 

    $answersql = 'INSERT INTO Answer (SessionId, QuestionId, Answer) VALUES (?, ?, ?)'; 
    if (!$insertanswer = $mysqli->prepare($answersql)) { 
     // Handle errors with prepare operation here 
     echo __LINE__.': '.$mysqli->error; 
    } 


     //make sure both prepared statements succeeded before proceeding 
      if($insert && $insertanswer) 
      { 
       $sessid = $_SESSION['id'] . ($_SESSION['initial_count'] > 1 ? $_SESSION['sessionCount'] : ''); 
       $c = count($_POST['numQuestion']); 

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

$insert->bind_param('sis', $sessid, $_POST['numQuestion'][$i], $_POST['questionText'][$i]); 

     $insert->execute(); 

     if ($insert->errno) 
     { 
     // Handle query error here 
     echo __LINE__.': '.$insert->error; 
     break 2; 
     } 


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

     $lastID = $insert->insert_id; 



     foreach($value as $answer) 
     { 
     $insertanswer->bind_param('sis', $sessid, $lastID, $answer); 

     $insertanswer->execute(); 

     if ($insertanswer->errno) { 
     // Handle query error here 
     echo __LINE__.': '.$insertanswer->error; 
     break 3; 
     } 
     } 
     } 
     } 

       //close your statements at the end 
       $insertanswer->close(); 
       $insert->close(); 
      } 
      ?> 

后续代码var_dump（$ _ POST）显示了这个以下：

array(4) { 
    ["numQuestion"]=> array(2) { 
     [0]=> string(1) "1" 
     [1]=> string(1) "2" 
    } 
    ["questionText"]=> array(2) { 
     [0]=> string(20) "What is 2+2 and 3+3?" 
     [1]=> string(41) "Which three items will you find in a car?" 
    } 
    ["submitDetails"]=> string(14) "Submit Details" 
    ["value"]=> array(2) { 
     [1]=> array(2) { 
      [0]=> string(1) "A" 
      [1]=> string(1) "C" 
     } 
     [2]=> array(3) { 
      [0]=> string(1) "A" 
      [1]=> string(1) "B" 
      [2]=> string(1) "D" 
     } 
    } 
} 

Answer 1

你有一个循环嵌套问题。如果我的理解正确的话，那就是运行问题和答案。问题是他们应该彼此独立。在你的代码中，相反，foreach在每个问题上运行，导致答案被插入两次。

这应该工作：

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