如何从可能的答案列表中检索不正确的答案 [英] How to retrieve incorrect answers from a list of possible answers
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;
?>
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