如何从可能的答案列表中检索不正确的答案

本文介绍了如何从可能的答案列表中检索不正确的答案的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

使用下面的代码，我试图通过首先完成问题的Option Type，然后从答案列表中删除正确的答案(Answer字段`)来检索可能答案的列表.

With the code below I am trying to retrieve the list of possible answers by first finishing a question's Option Type and then removing the correct answers (Answer field`) from the list of answers.

我的问题是，我只需要一点帮助就可以完成代码了.我在$row变量中得到了一个通知，我知道我没有在if语句之前调用它来引用它，但是我的问题是$row变量应该设置为或需要什么打电话给$row其他?

My question though is that I just need a little help finishing the code off to be able to do this. I am getting an notices in the $row variable where I know I have not called up on it before the if statement to refer to it but my question on that is what is $row variable suppose to be set as or do I need to call $row something else?

收到示例通知:

注意:未定义的变量:行在...上一行...

Notice: Undefined variable: row in ... on line ...

注意:试图在...上获取非对象的属性...

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

如果您在最底端查看代码，则当我尝试显示不正确的答案时，另一个问题将出现.<?php echo $incorrect_ans[$key]; ?>它始终显示单词Array.我是否错误地调用了阵列?我希望它显示收到的错误答案.

Another is issue if you look at code at the very bottom, when I try to display the incorrect answers <?php echo $incorrect_ans[$key]; ?> It keeps displaying the word Array. Am I calling the array incorrectly? I want it to display the incorrect answers recieved.

下面是完整的代码

$query = "SELECT q.SessionId, s.SessionName, q.QuestionId, q.QuestionNo, q.QuestionContent, an.Answer, an.AnswerId, q.QuestionMarks, q.OptionId, o.OptionType FROM Question q INNER JOIN Answer an ON q.QuestionID = an.QuestionID INNER JOIN Option_Table o ON o.OptionID = q.OptionID INNER JOIN Session s ON s.Sessionid = q.Sessionid WHERE s.SessionName = ? ORDER BY q.QuestionId, an.Answer "; // prepare query $stmt=$mysqli->prepare($query); // You only need to call bind_param once $stmt->bind_param("s", $assessment); // execute query $stmt->execute(); // This will hold the search results $searchQuestionNo = array(); $searchQuestionContent = array(); $totalMarks = array(); $searchAnswerId = array(); $searchMarks = array(); // Fetch the results into an array // get result and assign variables (prefix with db) $stmt->bind_result($dbSessionId, $dbSessionName, $dbQuestionId, $dbQuestionNo, $dbQuestionContent, $dbAnswer, $dbAnswerId, $dbQuestionMarks, $dbOptionId, $dbOptionType); while ($stmt->fetch()) { $specialOptionTypes = array( 'Yes or No' => array( 'Y', 'N' ), 'True or False' => array( 'T', 'F' ), ); // Do this for each row: if ( array_key_exists( $row->OptionType, $specialOptionTypes ) ) { $options = $specialOptionTypes[ $row->OptionType ]; } else if ( preg_match( '/^([A-Z])-([A-Z])$/', $row->OptionType, $match ) ) { $options = range( $match[1], $match[2] ); } else { // issue warning about unrecognized option type $options = array(); } $right = str_split( $row->Answer ); // or explode() on a delimiter, if any $wrong = array_diff( $options, $right ); $searchQuestionNo[] = $dbQuestionNo; $searchQuestionContent[] = $dbQuestionContent; $incorrect_ans[] = $wrong; $searchAnswerId[] = $dbAnswerId; $totalMarks[] = $dbQuestionMarks; $searchMarks[] = $dbQuestionMarks; } .... //table row <td class="answertd" name="incorrectanswers[]"><?php echo $incorrect_ans[$key]; ?></td>

如果您想查看数据库表以查看每个表中的内容，请查看以下内容:

If you want to see the database tables to see what is in each table then have a look below:

数据库表结构:

会话表(又名考试表)

SessionId(auto) SessionName 137 XULWQ

问题表:

SessionId QuestionId QuestionContent QuestionNo QuestionMarks OptionId 137 1 Name 2 Things 1 5 5 137 2 Name 3 Things 2 5 2

Option_Table表:

Option_Table Table:

OptionId OptionType 1 A-C 2 A-D 3 A-E 4 A-F 5 A-G 6 A-H

答案表:

AnswerId(auto) SessionId QuestionId Answer 200 137 1 B 201 137 1 F 202 137 2 D 203 137 2 A 204 137 2 C

更新:

现在唯一的问题是错误答案的布局，我希望它在每个问题的单独行中显示每个错误答案:

Only issue now is the layout of the incorrect answers, I want it to display each incorrect answer in its own row per question:

因此，让我们说以下是每个问题的正确答案和错误答案:

So lets say below are the correct and incorrect answers for each question:

Question Number: 1 Correct Answer(s) B Incorrect Answers A C D Question Number: 2 Correct Answer(s) A C Incorrect Answers B D Question Number: 3 Correct Answer(s) D Incorrect Answers A B C

以下显示了当前布局及其布局方式:

Below shows the current layout and the way it should be laid out:

当前输出的代码是这样的:

The code for the current output is this:

<table border='1' id='penaltytbl'> <thead> <tr> <th class='questionth'>Question No.</th> <th class='answerth'>Incorrect Answer</th></tr> </thead> <tbody> <?php $row_span = array_count_values($searchQuestionNo); $prev_ques = ''; foreach($searchQuestionNo as $key=>$questionNo){ ?> <tr class="questiontd"> <?php if($questionNo != $prev_ques){ ?> <td class="questionnumtd q<?php echo$questionNo?>_qnum" rowspan="<?php echo$row_span[$questionNo]?>"> <?php echo$questionNo?><input type="hidden" name="numQuestion" value="<?php echo$questionNo?>" /> </td> <?php } ?> <td class="answertd"><?php echo implode(',', $incorrect_ans[$key]);?></td> </tr> <?php $prev_ques = $questionNo; } ?> </tbody> </table>

推荐答案

$row的问题非常简单-没有定义变量$row.无需获取行，而是将变量绑定到结果值，因此只需将$row->OptionType替换为绑定变量$dbOptionType，将类似的$row->Answer替换为$dbAnswer. 要获取行，您应该这样做:

Problem with $row is pretty simple - there is no variable $row defined. Instead of fetching rows you're binding variables to result values, so just replace $row->OptionType with bound variable $dbOptionType and similar $row->Answer with $dbAnswer. To fetch rows you should rather do it this way:

$stmt->execute(); $result = $stmt->get_result(); while ($row = $result->fetch_object()) { // ... }

在示例代码中，我也没有看到定义的$incorrect_ans变量，也许您正在其他地方执行此操作，但是如果没有，则在其中定义其他列表的地方添加$incorrect_ans = array()(在// This will hold the search results行下方).

In example code I don't see also $incorrect_ans variable defined, maybe you're doing it somewhere else but if not then add $incorrect_ans = array() for example there where you're defining other lists (below // This will hold the search results line).

尝试在$incorrect_ans上执行print_r，然后您将看到结果数组的结构，这里有数组列表，这就是echo $incorrect_ans[$key];生成Array的原因.您可以执行echo implode(',', $incorrect_ans[$key]);，并且会得到字符串，字符串中的值由,字符分隔.

Try doing print_r on $incorrect_ans then you'll see structure of result array, you've got there list of arrays and thats why echo $incorrect_ans[$key]; is resulting in Array. You can do echo implode(',', $incorrect_ans[$key]); and you'll get string with values separated by , character.

我建议在while循环之前定义$specialOptionTypes，因为您没有在循环内更改该数组，所以我认为没有理由在每次迭代时都重新创建它.

I'd suggest to define $specialOptionTypes before while loop, you're not changing that array inside a loop so I suppose there is no reason to recreate it on every iteration.

我还注意到您正在将name属性设置为<td>，而该属性没有这样的属性(据我所知)-也许您想使用某些<input>?

I noticed also that you're setting name attribute to <td> which does not have such attribute (as far as I know) - maybe you wanted to use some <input>?

<?php // ......... $query = "SELECT q.SessionId, s.SessionName, q.QuestionId, q.QuestionNo, q.QuestionContent, an.Answer, an.AnswerId, q.QuestionMarks, q.OptionId, o.OptionType FROM Question q INNER JOIN Answer an ON q.QuestionID = an.QuestionID INNER JOIN Option_Table o ON o.OptionID = q.OptionID INNER JOIN Session s ON s.Sessionid = q.Sessionid WHERE s.SessionName = ? ORDER BY q.QuestionId, an.Answer"; // prepare query $stmt=$mysqli->prepare($query); // You only need to call bind_param once $stmt->bind_param("s", $assessment); // execute query $stmt->execute(); // This will hold the search results $searchQuestionNo = array(); $searchQuestionContent = array(); $totalMarks = array(); $searchAnswerId = array(); $searchMarks = array(); $incorrect_ans = array(); // Fetch the results into an array // get result and assign variables (prefix with db) $stmt->bind_result($dbSessionId, $dbSessionName, $dbQuestionId, $dbQuestionNo, $dbQuestionContent, $dbAnswer, $dbAnswerId, $dbQuestionMarks, $dbOptionId, $dbOptionType); $specialOptionTypes = array( 'Yes or No' => array('Y', 'N'), 'True or False' => array('T', 'F'), ); while ($stmt->fetch()) { // Do this for each row: if (array_key_exists($dbOptionType, $specialOptionTypes)) { $options = $specialOptionTypes[$dbOptionType]; } else if (preg_match('/^([A-Z])-([A-Z])$/', $dbOptionType, $match)) { $options = range($match[1], $match[2]); } else { // issue warning about unrecognized option type $options = array(); } $right = str_split($dbAnswer); // or explode() on a delimiter, if any $wrong = array_diff($options, $right); $searchQuestionNo[] = $dbQuestionNo; $searchQuestionContent[] = $dbQuestionContent; $incorrect_ans[] = $wrong; $searchAnswerId[] = $dbAnswerId; $totalMarks[] = $dbQuestionMarks; $searchMarks[] = $dbQuestionMarks; } // ......... for ($key = 0, $cnt = count($incorrect_ans) ; $key < $cnt ; ++$key) : ?> <td class="answertd"> <?php echo implode(',', $incorrect_ans[$key]); ?> </td> <?php endfor; ?>